Always try to improve society rather than just take from it. Until then, lawyer stuff. Copying, duplication or transmission of this material whole or in part is not permitted without the written permission of the author. The contents of this text are for illustrative purposes only. Those using this information do so entirely at their own risk. Errors and omissions excepted. Contents subject to change without notice. All material herein is subject to copyright, patent and other intellectual property rights. All rights reserved. Copyright (C) J.Partridge. 2003. 2007.

Due to the rise of parasitic lawyers and appalling New Labour laws, no person may read this nor act upon this information.
Have a nice (lawyer free) day.

This page is NOT for gas guzzlers, Guantanamo - rendition, US marines and their CIA overlords, New Labour voters, lawyers, Freemasons, KKK, dodgy religions, or any who support corruption, torture or lies. Please make a nice world, don't make it any nastier.
Say NO to second home owners displacing the locals in Plymouth and all coastal towns and villages. (They also mess up the centuries of heritage with the awful messes at Gunislake and the Barbican. They destroy Britain, with whom I consider their co-criminals, the council planners and developers with their 'dodgy hand shakes'.
So please, never, never help second home owners.
Most of us may remain poor, but at least we should live in our own villages. This way, Devon and Cornish villages will once again return to lively places rather than become ghost villages. Visitors living on moorings or hotels or guest houses is fine, but always say NO to second home owners. Always work to make Britain better for the British.

I was recently swimming with many others at Bovisands when a family in a speed boat anchored a few yards off the centre of the beach, when the charts and buoys show the navigation for boats onto the beach is along the south edge. It would not be so bad if he had beached the boat, or anchored away from the swimmers. But the twat anchored exactly where most of us swimmers were. This is just one of many thousands of complete assholes known locally as 'boaties' who come to the Southwest who show no concern for others. He even left a thick cord between the boat and a toy floatation aid on the shore, so we all had to dive under or step over it, stopping many of us from doing widths of the beach. He could easily see he was upsetting many of the bathers, yet showed no interest other than to swear at us when we mouthed words of hassle concerning his boat and cord. He was acting like a politician, freemason, lawyer or police inspector. Luckily, his outboard would not start and I observed he had lost electric power to start it. Two days before, I had rewired a similar system and could have fixed it for him in a few minutes. I did not to help such a bastard as it would at least prevent him and his awful family from upsetting others around our coast with their bad manners and appalling lack of any maritime skill. If nothing else, not helping such a ignorant bastard could save a call out for the lifeboat should the prat fail to start in deeper waters. Being stuck here, may even cause the asshole to reconsider boating. I later passed the asshole who acted like a complete ignoramus on my way back up the path to the road, where he and his family barged past people with no concern for others. Quite frankly, I hope the boat gets stolen and he goes back to London or wherever, and never returns.
(Frankly having seen some of the 'boaties' in Plymouth, I'd prefer to let them drown, to leave the seas for those who know how to politely enjoy our fine country.)
This happens all the time and these assholes are encouraged by the City Council, often freemasons and their developers with second homes. We locals regularly get pissed off with so many of these bastards, so never help them, just encourage them to bugger off.

If asked to work for freemasons, second home owners and such like, who often need the skills of locals, you may wish to tacitly check if they own a second home nearby. If a so, always make some excuse not relating to your need to live locally in affordable housing and let the bastard look elsewhere, preferably for someone who will do a crap job and charge them excessively, to encourage the bastard to bugger off elsewhere. If you desperately need the work, then always overcharge as much as you possibly can, at least four times the normal cost, so it can help pay towards local housing - for local people.

Boat Wiring.

The basic wiring begins with charging circuit.
In most cases, be it diesel or petrol, there will be an alternator attached. Perhaps a small integral alternator inside the flywheel of a single cylinder manoeuvring engine on a yacht. Or a car alternator on a dual cylinder diesel or perhaps on a marinised car engine or something similar but more expensive on the larger specialist marine engines.
Larger generators are rarely used unless in large ships, although I've worked on steam turbine and V12 diesel generators on large ships, which makes smaller craft far easier to enjoy.

Alternators.
For the average reader, the electrical generation device will be a car style alternator running off a simple Vee belt. With the marine engine plonking its steady beat all day, this is a very reliable situation, as the belt only passes the power needed, with no extra acceleration or deceleration, and as such the humble Vee belt on a boat seems to last forever. Just make sure the alternator spins fast enough at manoeuvring and plodding speeds to keep up with the needs of any night time work such as deck lights on a working boat.
Always carry a spare belt and the spanners (wrenches) to adjust and replace the alternator belt.

For the best maintenance, a standard car alternator often suffices, so it is recommended to simply buy two identical alternators from a scrap yard, then test both and store one on the boat. The best alternators have integral regulators, and these need just two wires. It is possible to repair alternators, but having a working one ready for replacement makes sailing far safer and easier.

If you don't have an alternator or other generator, then if there is a vee belt pulley on the engine, about the same diameter as the pulley on the alternator, then all is well. Make up a steel bracket to mount the alternator on its main bolt bracket, such that it's in line with the pulley and positioned so it remains dry. Then buy a vee belt to fit, (they come in a large range of standard sizes from your local car shop), then make up an adjuster to maintain tension.
If the drive belt is already used for other items, then welding a similar Vee pulley to the present item to allow a second Vee belt is straight forward. (See Hulls monograph.)
If there is a chance of water splash, then always fit a splash guard, even if it's only a piece of an old plastic oil container.
Of course, for more pragmatic people, the alternator need not be marinised as the windings are lacquered and the carbon brushes rub constantly against the slip rings. Just an occasional squirt of maintenance spray to prevent slip ring corrosion and then only if in a damp environment. Also, as alternators are cheap in scrap yards (10 quid), then a spare one sealed in a plastic bag in a dry part of the hold is money well spent.

(To marinise an alternator, it must be taken apart and the bare parts of the slip rings carefully lacquered or epoxied, the windings given an extra coat of marine lacquer and internal connections lacquered or hard epoxied. The air vent to the alternator should also be filtered and splash proofed. The regulator box re-seated with heat dispersing grease (from computer shops) to prevent salt water corroding the heat path. The brushes re-inserted with a thin film of silicone grease and the springs given a thin film of lacquer or covered with soft epoxy which allows flexibility. The electrical connections should be sealed with silicone sealant. All bolts to be stainless steel or refitted with copper grease and if the alloy casing can be anodised, then do so. Carrying a spare alternator is a far better option.
(If the customer is a second home owner, then their alternators are always special and must be replaced with the original manufacturers item, which takes many days to get, and costs lots. If parts are unavailable then you should charge according to the needs of saving for a local home.)

In small engines such as outbards, the alternator is a simple set of windings inside the flywheel and just a simple output wire to a regulator rectifier control box may be all that is needed. Sometimes even this is internal.
On one boat, we simply scrapped the old alternator and fitted one from a Ford Fiesta for a tenner. It has worked happily for years. 13.8 volts is the same the world over and perfectly suitable for any 12 volt system charging.

The car style alternator has two or three wires leading out - two identical thick red wires delivering the regulated 13.8 volts, and a smaller warning light wire. The earth connection is done through the metal engine.
The power from the alternator is taken to the battery and need have no fuses or other items in line as the alternator is normally connected in this manner on all vehicles.
To make wiring easier and more reliable, the thick 12 volt wire from the alternator is normally connected to the stud on the starter solenoid which also goes to the battery positive, (via the isolator switch) See diagram, later. This ensures the power from the alternator is reliably connected through a very thick wire otherwise unused for most of the time, it also saves wiring and is far less easily damaged.
Likewise the earth from the alternator casing is going to earth via the physical mounting on the engine, so the large earth cable (for the starter motor current) from the engine crankcase to the battery earth is more than adequate for charging the battery.
Therefore the two most important electrical items on a boat, starting and charging - are perfectly catered for.

The battery stores the electricity from the alternator, then passes this into the rest of the boat through an isolator switch.
The isolator switch ensures that when anchored for months, there will be no power loss other than those items you decide to tap off directly, such as automatic bilge pump and perhaps a low power anchor or mooring light.
The only other items connected to an isolated battery may be a solar panel or wind turbine for long term trickle charging.
The simplest isolator is an on / off switch, although other types have an integral terminal to the battery for bilge and solar charging if needed, but is not always necessary. If out of water, then simply disconnect the battery.

The battery supplies its stored power to the isolator switch via a heavy duty cable.
A heavy duty (red) cable from the isolator switch supplies the battery power directly to the starter motor along another length of heavy duty (red) cable.
The battery also has a second heavy duty cable from the (Earth) negative side to a large bolt on the engine casing. This completes the circuit for the starter motor to get all the power the battery can supply.
Note: A few boats use positive earth - check first.
The main power cable is normally coloured red and the earth cable usually black.
The chandlers often charge lots for these cables, so look around.
For smaller custom boats such as with small and medium outboards, I prefer specialist silicone covered heavy duty cables with specially wound copper wire. This has the advantage of the silicone being semi transparent, so I can visually check for corrosion before any problems occur. The silicone also allows easy coating of my colour co-ordinated, moulded silicone terminals and the silicone also allows much easier and softer wiring routes with less chance of internal fracturing from constant flexing.
For big, permanently connected engines, I prefer certain types of heavy duty, solid or multi core copper cable, plus special attention to the terminals.
In some situations, such as V12 engines, I prefer to use heavy duty welding cable which is far more suitable than some of the stuff from ships chandlers.

The starter motor on the engine has a solenoid attached, which is just a heavy duty switch controlled by a small wire. This small control wire need only be given a small push button to supply 12 volts from the battery to the solenoid, and the starter will then crank over the engine, using all the power that the battery can supply along the heavy red and black cables.
The main solenoid problem is that its heavy internal switch can become pitted, so needs cleaning with a file, fine abrasive paper then polishing. Often the pitted bridge can be reversed to double the life expectancy.
If the solenoid fails, then it can occasionally be bypassed by a spanner across the main terminals. (This is the design I prefer for bottom line reliability - you can't easily repair or change a solenoid on the high seas).
Marinisation of the solenoid is simply to prevent corrosion, perfect terminals connections, and preferably only inspect and repair the internals on a hot, dry day to prevent corrosion. Adding grease in the wrong places of a solenoid can also reduce the reliability of the device.
The starter motor on which the solenoid sits must remain dry. Any access to the starter ring must be taped over during damp winters, but allowed to dry during the summer. The starter ring gear regularly lubricated with a stiff brush using thick grease, preferably with a little graphite, while turning the engine by hand. If there are crankshaft angle sensors in this area, as found on modern petrol engines, then never use graphite or lithium grease, just a little anti corrosion layer with silicone grease.
The front and rear starter shaft bushes should be lubricated every three years.

Never be tempted to place the battery near the engine or in the same compartment to reduce cable length, A hot battery will not last long. The battery should be kept cool for longevity and in a cool, dry part of the boat and thus may hold its charge three times longer.

Diesels.
Diesels do not use spark plugs, so can run without any battery until the fuel runs out.
The battery is only needed for starting, unless you have a hand crank starter - usually with a decompressor to get the revs up before releasing the decomp lever.
Some diesels, especially those derived from cars and the larger marine engines may also have heaters. Heaters are small heating coils which glow to warm the cylinders for easier starting. Heaters usually have about a ten second warming before starting the engine (see your manufacturers manual for specific details). This is easily wired through a power switch called a relay: Simply pressing a button for ten seconds to allow power from the battery to be switched through the relay to the heaters, to warm the combustion chambers before you press the starter button.

A lever is normally attached to the diesel injector block to stop the engine by preventing injection of fuel into the cylinders. This simply needs a small control cord or wire such as a push bike brake cable and a recessed red pull knob in the cabin or engine cover to stop the engine. Always paint this item yellow or red and 'ENGINE STOP' so it can be used in an emergency.

Petrol.
Petrol engines use spark plugs and as such either have old style points, or modern electronic ignition systems. These are usually specific to the engine, so should be wired according to the manufacturers instruction.
If a simple points system, then this is simplicity itself. Power comes from the ignition switch to the ignition coil then shorts out through the points on the engine. By switching off the power to the coil, the engine stops. See circuit diagram. Always carry spare set of points, condenser, ignition coil, HT leads, and spark plugs, available at low cost from scrap yard and car shops. (If a very old, reliable engine, then get a few spare points, rotor and covers. The other parts are usually available as equivalents for later engines.) I always recommend a spare engine management computer and emergency wiring system for custom boats.
To stop the engine, the power to the sparks system is simply switched off. An extra isolator button in the wire will allow an emergency stop button on deck.
I had an old Ford engine which used electronic ignition, but with a long heritage, it allowed the use of an earlier points distributor. This was tested and then removed and stored in a plastic bag should the electronic ignition fail - the best of both worlds. (Be safe before leaving harbour.)

Petrol in a boat can leak but unlike a car, cannot disperse out the bottom. On a boat, a petrol leak and any spark is asking for big trouble. So be particularly careful is using any petrol engine on a boat.

Fuel Injection.
The modern petrol systems may use fuel injection, so these will need more ancillary systems, including a high pressure fuel pump to pressurise the petrol into the injectors. Plus a set of sensors to measure the exhaust chemistry (Lambda sensor) the engine coolant temperature, air intake flow rate, throttle position, position and revs of the crankshaft and such like. These sensors send their various pulses to the engine computer which decides when and how long the fuel injectors will squirt fuel into the engine and when the sparks will occur.
Always make sure all connections are absolutely dry, clean and corrosion free. If there are sealing caps on connectors, always use them. I prefer to prevent the rubber caps from corroding by using silicone grease or a long term waterproof spray.

An advantage of fuel injection is that the engine can be run close to low fuel consumption and as such may include an anti 'knock' sensor. This is usually a microphone in the cylinder head to sense the knock, and allow the engine to run lean when under a steady load. For boats, this is ideal, so always look for such a sensor if choosing a petrol engine.

Hulls and earths.
Boats are different to other vehicles as their hulls are usually wood or glass and resin. Any metal hull should NOT be used as an earth due to corrosion problems. (Metal hulls must always have sacrificial zinc anodes to reduce the electrolysis between sea water and metals which acts as a weak battery and slowly erode the hull. This also applies to other non metal hulls where metal is connected, such as a prop shaft, rudder or heavy metal keel.)

For a wood, ferrocement or glass fibre hull, every part of the wiring will always need an earth wire.
Making room for safe routing of the main wiring is highly recommended when building up from a bare hull. Installing dual, redundant main wiring each side, with heavy waterproofed tap off points is recommended.
Inserting tubing into the bare hull to allow cables to run the length of the hull in total dryness can also make rewiring and cable routing easier. For example, a small bore plastic tube from the engine to the cabin and to the fwd winch. Adding closed cell foam can prevent rattling. Any tube from engine to cabin must be sealed at both ends to prevent engine fumes or carbon monoxide or other gas poisoning.

For the smaller ancillaries such as simple lights, dual core speaker wiring also makes life easier, one for 12 volts and the other for the earth return.
With dual core wire, wherever the boats' control switches lead out to the various lights and such like, there can also be a large earth block, which is then connected to the battery via a thick earth wire. This allows each item to have a separate pair of wires leading into the cabin which makes wiring easier and more reliable.

Connections.
For example, the simplest piece of wiring is a navigation light, such as an anchor light. The easiest way to wire this is to open up the light and connect a long length of dual core wire. (Sheathed wire as often found for simple domestic lights or video recorders and such like). White or black outer sheaths are commonly available. Buy a reel with a plastic colour to match the boat. On better boats, I may sometimes dye my cables to match the interior and exterior decor.
First measure out a length of wire to reach from the cabin switch to the light. Then allow a safety margin of about 10 percent extra length or a couple of extra feet.
The light is opened up and the wires connected to the internal tags. If the light or other device is polarised, then the red wire usually goes to positive and the blue wire is the earth. Usually the light fitting is non polarised such as a standard festoon lamp or screw fit or bayonet fitting lamp. Nevertheless, the lamp socket is normally earth and the insulated central connection is positive. This is because, should an earth backing plate fall off onto a metal hull, it won't cause the fuse to blow.

Festoon lamps are often recommended, and although they are old technology, they have certain advantages for boats. First is easy replacement in corrosion, where a screw or bayonet fixing is harder to replace, especially if corroded. The festoon is held between two spring bronze lugs, which makes replacement easy. The lugs also act as minor shock absorbers to help protect the delicate wire filament. Third, any corrosion in these bronze spring lugs can be easily seen, giving early warning for replacement. The other types have steel fittings, which are more prone to corrosion. Whichever type you have, always give a squirt of silicone maintenance spray before replacing the cover to reduce problems. If a screw or bayonet, then use silicone grease on the lamp fitting before climbing up the mast.

Connections can be done using crimp connectors or by soldering. If soldering, then the solder area must be painted or lacquered to prevent corrosion or covered in silicone sealant. If crimping, I prefer to dip the bare wire into silicone sealant before crimping, to prevent corrosion.

(When climbing up a mast to rewire, carry a small jar of nail varnish to waterproof the terminals. It's simple to use with its own paint brush and goes on thick and clear. A pale colour is better than clear varnish, as it ensures the lacquer is painted everywhere without missing any areas of potential corrosion. - A good use of those old nail varnishes whose colours are not fashionable this week. Bright colour varnishes can also be used to mark screws and bolts which must never work loose, so painting a mark or line over these allows a quick and easy check of potential vibration problems such as pipe lines, engine mounting bolts and all important threads. Likewise a cardboard nail file can clean up electrical contacts before you refit them. Warning: Never enter a handbag without permission. )

Once the wires are connected to the anchor lamp connections, the cable is often given a 'strain knot' inside the casing, so that any external pulling of the wire will not put strain on the connections, such as any rough handling when climbing up the mast, a mast collapsing or whatever else may happen at sea. The strain knot need be just a simple single knot in the wire. Where the wire exits the light housing, it is sealed with any supplied gland, grommet or waterproof socket, or sealed with a good dollop of silicone sealant.

The same applies for the other items, the navigation lights, deck lights, bilge pump and such like.
It is possible to wire up the navigation lights all on one wire. But if things go wrong, by having individual wires to each, they are less likely to all fail at once. At sea, there is no convenient repair shop. So if you have all the individual pairs of wires leading into the cabin, at least when everything else fails, you can bodge the wires to the battery to make a running repair, even in a hurricane.
Eventually the boat will have lots of neatly aligned wires leading back to the cabin. All pairs of wires will be labelled inside the cabin with strong masking tape and a permanent felt tip marker, ready for connection to the main control panel switches and fuses.

Only three items need be connected when the main isolator switch is off: The anchor light switch, the bilge pump set on automatic and a 12 volt socket for charging up your hand held phone or other emergency item.

Anchor light.
This white 360 degree masthead light is used when at anchor, and as such the rest of the boat electrics may well be unused. Therefore it runs from a separate circuit to all else. The anchor light needs to work independently when all else is disconnected by the isolation switch. Therefore there will be a wire from the battery to an easily accessible fuse near the battery, leading to a single anchor light switch, which then goes to the anchor light on the top of the mast. Check with chandlers for superior anchor lamps as standard car lamps are not so robust. See also Hulls monograph.

Bilge Pump.
The bilge pump is normally a little more complex, having an automatic and a manual position.
This uses THREE wires, one for earth, two to supply 12 volts. One of these supplies 12 volts to the motor direct for 'manual' use via a switch. The other 12 volt wire supplies power in 'automatic' mode to the bilge level sensor and thence to the motor so it can pump when no one is onboard. An earth wire is also needed back from the motor to the battery.
Always use a fuse when connecting directly to the battery.
Therefore a standard three core domestic sheathed wire can be used. This wire is commonly used for most domestic items, but as the bilge is safety critical, I always use the heavier 13 amp cable. (Using larger amperage domestic wiring, any corrosion is going to delay the chance of failure on thicker wire.)
The bilge automatic setting is always connected to the battery via a simple fuse leading to the bilge level sensor.
The bilge pump manual wire is connected only when the isolator switch is connected.
For the bilge pump, waterproofing is paramount, so always make sure any manufacturers waterproof connection is well above any potential bilge waterline and is always water tight. If you are connecting directly to the wires on the motor and to the bilge water level sensor, then always wrap the wires around the connections, then solder the wires, cover liberally in silicone sealant, cover the joints in heat shrink sleeving and use all sealing grommets and shields. The wires from the pump and the level sensor are then connected well above the waterline in a watertight box, or along a standard domestic sheathed three core wire to the main fuse box and switch area.
Some people like the bilge sensor to sink to the lowest part of the bilge, so any listing or such like will allow the sensor to reach the lowest part of the boat. Some prefer a fixed sensor, but it's up to the owner to decide and depends upon the design of hull. On a small round hull, a loose pump is common. On larger boats, two or more, well spaced bilge pumps are recommended.
Bilge buzzer. It's nice to know the bilge pump is working, especially on an older hull. To be on the high seas with the occasional buzz denoting her bilge is under control is highly recommended. When the buzzing gets too often for comfort, at least you are ahead of the situation and can consider reaching shore or looking for problems before they get too dangerous. I like buzzers.
Where a bilge pump warning light or buzzer or both are fitted, then these should be connected by using four core cable, with the fourth wire connected to the motor and leading back to operate the light and buzzer when the motor receives 12 volts.

(TIP. If you have a winter mooring, but don't want to get the dinghy out every week to check the battery, then simply fit a battery level indicator consisting of red, amber and green LED's to the cabin window so that it can be checked with binoculars from the shore. It is possible to fit a bilge water level meter, but the best way is to simply check the hulls waterline for anything serious. Always have a manual bilge pump as backup.
I build ten LED battery monitoring systems from 25 pounds which are adjusted to individual battery types and capacities. The danger level LED is particularly powerful, for a clear warning to shore that the battery needs charging or the solar panel has failed.)

Independent / emergency 12 volt supply.
It may well be necessary to have an emergency 12 volt supply, such as a cigarette lighter socket to charge up phones, or an emergency light on an extendible lead for repair when all else fails.
Such a circuit is often a pair of car cigarette sockets in the cabin and the same in the engine compartment and perhaps near the bilge pump if this is not in the engine bay. The emergency circuit is a pair of independent thick wires from the battery positive and negative, with a 15 amp fuse near the battery. (Higher fuse rating if you use power tools.)
Always use silicone sealant to prevent corrosion on all connections. Always fit a waterproof seal over the socket ends, or use a thick piece of bright yellow vinyl tape which can seal perfectly but can be easily removed. Only a fool leaves an emergency power supply with the seal open to the weather.
As you may be adrift trying to make running repairs at night with a dead engine, then any emergency lights must always be low power devices so that the battery will not be run down while powering emergency lighting, and will still have enough reserve to start the engine afterwards. Therefore make sure all emergency lights are low power items, preferably LED.

Neatness and physical protection.
I have worked on many incredibly horrible, messy wiring looms. Neatness is paramount.
If the wiring cannot be easily understood by someone else, then it's nowhere near good enough.
For many boats, the wiring loom can get messy, but there is a simple solution care of the carvaning folk. It's called seven core trailer cable and makes an excellent instant wiring loom betwixt cabin and engine room. The main heavy duty wires between battery, cabin and engine bay remain in place. Minor wiring can also be done through seven core cable.
The seven different coloured wires can be used as you wish. Always note that the heaviest of the seven should be used as an earth, even if you have a decent earth cable from the battery to the engine.
Alternatively if using a separate earth cable through the hull, you may wish to use the thickest of the seven as a 12 volt supply any high drain components or critical items.
The other wires can be used to supply 12 volts for the starter, take the alternator sense warning wire, oil pressure light, water temperature sensor, power to the ignition coil or as a kill switch and such like. Also any echo sensor. If you need more wires, then you may also be able to buy nine core trailer cable or use two seven core cables, one for the engine, one for the hull fittings.

If a fancy boat needing more than seven or nine wires, you can always have two sets of cables - one leading to each of the engines and another to the lights and ancillaries control box.
In special boats, or where more than about a dozen wires are needed, I prefer to build my own custom looms. (See the wiring monograph on my website for loom building.)

As will be found, all these wires leading into the cabin will cause confusion, so always use sensible colour coding and clear masking tape on each cable, marked with the item it is connected to. Always leave these pieces of tape in place for future reference. If you have red, green and white electrical tape, then these can also be used to demote which lights they supply.

Colours.
The normal recommendation for wiring is to have the main 12 volts in red. The earth is normally black.
Other colours are up to the reader, but perhaps green for starboard, brown for port, white for anchor and yellow for navigation lights. I always keep red as 12 volts for general use, and if not used then it can become an emergency 12 volt socket or waterproof connection.
But the choices are yours and whatever seems most logical.
Always make a clear wiring diagram as you wire up your hull. Upon completion and testing, make three neat copies and seal them in laminated plastic waterproof film. Two copies in the boat, and one as builders reference and archive. I still have reference wiring diagrams from twenty years ago, as many owners prefer reliable designs.

An example of a simple wiring diagram. A very basic diesel boat with a car alternator, engine area to the left. Diesel heaters in magenta, and a petrol engine with points in blue. I was recently line fishing in the English channel on this boat into the night. Power for the Fish finder and GPS are taken off the spare fuses as needed, preferably with in-line filters to prevent stray spikes in the electrics.

Sometimes a long length of wire may need to be split part way to reach an item. In such cases, it's often easier and safer to use a separate, new single length of cable rather than compromise the sheath of a cable leading the length of the hull. Done properly, the wiring is likely to last much longer when it has no weak areas where it can bend or fray or loose its outer protective sheath. I have known some commercial wiring looms from the biggest boat builders to be corroded just three years from being built.

The sizes of the wires will depend upon their needs, but as all such items are common in nature to road vehicles, then the wire sizes available are perfectly adequate and marinsed wiring is rarely needed if built properly.

Larger boats often use 24 volt systems and these too are available in trucks and busses. Any 12 volt devices can then use a 24 to 12 volt interface or a special regulator or 99p regulator chips, e.g. 7812.
24 volt systems do not need heavier wire, just good insulation. Normal car wiring can carry 24 volts with no problems and will allow twice the power through the same cable. Volts x amps = watts. Therefore the same wire carrying 24 volts can deliver twice the power of a wire carrying 12 volts.

Only the main starter cables may cause real concern. Therefore it's important to check with the original heavy duty wiring and match this for thickness to ensure it can carry the starter load without overheating. If in doubt, always choose heavier wiring, as there is less chance of long term corrosion.
For the thick cables, always buy heavy duty end terminals for the battery and engine and starter connections. These are often screw connections at the battery terminals, but at the engine end, you will need large eyelets or to look for similar screw clamping terminals which can be bolted to the engine casing and the starter motor terminal. Always used anti- corrosion plated items. Where the cable is not totally secure in the screw terminals, either pack it with copper or double over the cable. Always check by trying hard to pull the cable out of the terminal. Then securely seal with silicone sealant. Many batteries use bolted terminals, whereas others use the old tapered post design. I prefer the tapered post design as it allows quick maintenance if it loosens, by simply pushing on harder and twisting, the post automatically cleans the terminal of any slight corrosion which can cause resistance and heating. The tapered pin designs also permit easy removal in emergency and because the pins are different sizes, prevents boaties from connecting the battery up wrongly.
The bare heavy duty copper cable is stripped back to fit neatly into the terminal and then crimped. If you do not have the heavy duty crimpers, then use whatever heavy duty pliers or a vice as available. If needed, use a shaped clamp, then hammer the terminal to close over the cable. Then heat and sink a lot of solder into the crimped join, clean off any flux and then smother with silicone sealant. This often needs a flame source as a soldering iron is rarely up to the job. Micro blow lamps are particularly good. Finally sleeve with heatshrink or plenty of vinyl electrical tape of the correct colour. The heavy duty cable is then run alongside a bulkhead using cable ties to keep it neat and free from vibration abrasion or bilge water.

The cabin control area.
All the lights and engine are wired, with lots of marked cables neatly entering the cabin or control area.
They should all be neatly bundled according to their uses and routing, with no strain on any cable, with neat and abrasion resistant positioning. They should be easy to route past the throttle and steering gear, up to the fuses and switches.
As the better cabin control panels hinge open for inspection, then the cables are run along the hinge line for neater alignment and zero strain. A good control panel should be able to be lifted up to access the components, and I personally prefer to include a small foam filled box with screwdrivers, pliers, fuses, bulbs, spare wire, a 12 volt soldering iron and solder, and an automatic emergency light to illuminate the area.

Making your own control panel is often fun, but always make sure the switches are positioned logically. If you don't like the first attempt at a control panel, then by leaving plenty of spare wiring on the end of each cable will make life easier - so always have a neat loop or S shape path of cable tied back for any future problems or rebuilds.
Where the control panel folds up or sideways, all the cables should be laid along the line of the panel hinge so that there is no strain on the wiring.

The horn button must be clear and easy, especially if working on deck and you see an idiot in a speedboat heading your way. I prefer to paint the horn button yellow with a horn symbol.

The ignition switch should be positioned out of the way, along with the starter button and any diesel heater button. If using a key, then this must not be brushed against in heavy seas, as it may break off and fail to work, or may gouge your arm. Consider a recessed key or mounted out of the way, or perhaps with nudge protection side blocks will make for a little more safety on a rough sea.
Always fit covers over the starters and any heater buttons, or if you have kids or are a boatie. Also fit a cut-out relay so they cannot work when each engine is running if they are not out of the way.

The warning lights and gauges are often arranged in a bank. If using two or more engines then the co-pilot, throttle-man or engineer must be consulted. Many racing machines have the 'red line' positioned vertically for easier visual reference.
For a single engine, personal choice is used especially if you don't remember to keep an eye on oil pressure, so this gauge and light should be especially clear, and perhaps marked with a yellow gauge bezel and add a buzzer.

If you often use dead reckoning, then the engine revs may be important. (Especially after you have graduated the rev counter with extra marks denoting the (clean) true hull speed after testing during sea trials in still waters).

Lots of fancy switches may impress boaties and other prats, but most instrumentation is only needed for the truly important items.

On working boats, where the crew are on deck with the boat chugging along the nets or pots, then repeater warning lights may be added where easily seen and an emergency engine stop on the deck - well siliconed to prevent corrosion and under a yellow plastic cover.
If you sail solo, then it's recommended to have an engine kill switch extension on the working deck space, with a removable plug connected to a waist cord, such that if you fall overboard, (apart from having a line of floats trailing behind), the waist cord pulls out the kill button connection so the engine cuts out. If sailing or motoring, pulling the trailing line pulls the rudder hard to one side. (The bright trailing polypropylene rope is attached to the rudder mechanism along with an engine kill switch).

Always sit in the cockpit control seat and decide which items you use or read the most, then pencil in the most ergonomic positions for the control systems. Make sure no item can be accidentally switched on or off and assume it will always be a wet night in heavy seas when using the control panel. Slap you hand hard down on the control panel and ensure nothing has changed. Never skip this part of the building process and never position the controls for posing purposes. On large boats, I recommend making paper dials and switches, then constantly repositioning them with sticky putty until the layout is perfect. On fancy larger boats, photo copy the actual dials and controls, print them full size, then arrange for true safety rather than posing perfection.
See Hulls monograph for more info and alternative display and control systems.

(You may wish to add a pair of car jumper cables and a small tool kit beside the control panel or near the engine and a waterproofed circuit diagram, along with a spare fuel filter, Vee belt, points and spark plugs as needed.
(If a yacht in a thunderstorm, then connect the jumper leads to the metal side stays and dangle the free ends in the sea to prevent the nastier effects of lighting strikes.)

Fuses.
Before any power goes to switches, they must be protected through a fuse box.
Fuses must be used and are chosen according to their uses.
It is common practice to fit a separate fuse for almost each and every circuit.
A decent fuse can be fitted between the alternator and the battery, especially if you think the alternator may become submerged.
A main fuse from the battery isolator switch to the ignition switch, must be capable of all the power needed and then an extra 10 percent for safety.

Volts x amps = watts.
(Imagine water in a pipe - Volts is the pressure, Amps if the flow of current, and Watts is the power from the combination of these two. You can have high voltage and low pressure in an ignition coil, or low voltage and massive flow to the starter motor. In most cases, such as a light, will have 12 volts and about 1 to 5 amps.)

For example, if the ignition switch supplies the navigation lights, plus the cabin light, and the digital control panels, radios, echo sounder and GPS, then adding all these up, you get for example, 80 watts, then the fuse should be able to supply 80 watts divided by 12 volts = 7 amps. So a 10 amp fuse would be ideal.
Using a 7 amp fuse to power a 7 amp system is placing the fuse close to its limit and it WILL fail much sooner. As the fuse should blow only when the load exceeds a safe limit, then using a slightly higher rated fuse will allow some leeway on the design and variables in the system and will safely allow for some ageing.

The ignition switch is normally a heavy duty item. This then supplies power from the isolator switch to the ancillary fuse box.
If the main switch needs more then the rated current, then the ignition switch can be augmented with relays for less important items, to help take the load of the important items connected directly through the ignition switch.
Please note, an ignition switch is not needed for everything, just for those items needed for security, and prevent theft or other unwanted use.
The ignition switch can supply a bank of fuses, often a bank of neat fuses in a row and out of the way, but ready to access.
(Consider a spare set of fuses fitted nearby, plus a small emergency torch (flashlight).)
These fuses can supply the navigation lights, compass light, cabin lights, power to start the engine, (starter button), echo sounder, GPS etc.
Always have any fancy engine management computer on a separately fused circuit which is also given an in line filter to prevent spikes from other electrical items and can be switched off by the ignition switch.
On large boats, where the screens for GPS, radar, repeaters and such like need plenty of power, then a separate circuit and bank of fuses is recommended and the ignition switch may supply power to these via robust relays.
If the rudder is controlled via the GPS, so a solo user can get some kip, then this must have a robust and totally reliable power supply, often with dual or back up systems.

Fuses must also be sea proof, so always look for rubber O ring seals in the fuse cover. The best designs would be flush fitting or slightly raised fuse sockets which just need a half turn to replace the fuse. As many are now flush fitting, I glue a lug to make them easy to remove by hand, rather than look for a screwdriver in high seas. I also prefer to paint the removable part yellow should it fail in a storm and can be found easily swilling around a wet deck. Again, placing a few spare covers as well as spare fuses nearby is recommended as these cost just a few more pennies.
(I often use sticky blue office putty to hold small items where they are needed most. For example a spare festoon lamp can be blue tacked into the casing of navigation lights so you only need to have a screwdriver tied to your wrist and an elasticated head lamp holding on your hat when climbing a mast at night. Ideally, if using the boat nightly, you would have two lamps in each light, so that you can replace the failed one when safely back in harbour should an important lamp fail. )
Prepare now, when you have the time, not at sea when you need it to be reliable.

If you are wiring for an idiot or boatie, or not too happy about parts of the wiring, or have dubious or unreliable equipment, then the fuses may be replaced by thermal fuses. These trip-out when the current gets too high. The fuse then cools and can be reset by pushing a reset button to reconnect and thereby save having to fiddle with separate fuses. This does not mean it solves the problem, merely saves having to replace fuses. All to often 'boaties' keep pressing the thermal reset button and cursing, but have no idea of the underlying causes or need for repair.

Switches.
This comparatively small supply of power to the lights and ancillaries can all be through the ignition switch, to the bank of fuses and on to the appropriate minor switches.
Modern chandlers can supply neat little fuse and switch banks ready wired for easy installation. (They are often half the price if you buy on the internet.)
If making your own, then always look for switches which meet the style and needs of the boat. They must be able to survive being elbowed in a hurricane and not break. So simple rocker switches are often recommended rather than the more fragile lever switches. (The first moon lander had a rocker switch break off, and likewise, your boat may also be in jeopardy.)
If making a plywood control panel, then extra plywood can be inserted between switches to be flush to prevent accidental use and reduce injuries in high seas. Then the switches are removed, the whole dash board smoothed and sculpted, then painted or varnished to a decent finish, then printed with lettering (e.g. lettraset) then varnished. (See also Hulls monograph - throttle and gearbox controls.)
Switches with silicone rubber covers are popular, but always have at least three spare waterproof covers should a broken halyard or hook rip these soft switch covers.

Always be safe from the outset by good design.

If using ordinary car components because chandlers are overpriced, then a few points of note:
If using a car isolator switch which is not sealed, such as the removable taper pin metal design, then a dab of silicone grease helps prevent corrosion when the key is out, but always make a plastic cover, bung or seal for the key hole. If a sealed item, then this is just as good as any marine item unless it's out in the open, whereupon some waterproof cover or seal is recommended.
Car crimp connectors (often noted by the yellow, blue and red crimps) are abysmal and used by many thousands of marine service centres. I particularly hate them and would never use them, even in a road vehicle. The best are sealed connectors, as available in certain places if you know your trade. Where multi pin connectors are used, then I always use sealed designs with rubber grommets and seals. At present, some Italian components are best, followed by certain Japanese components. I charge highly for fitting these items and have no problems because they are always worth the extra cost.

Warning lights.
Warning lights should be able to warn in all situations, so they should not be hidden from any sailing position.
Warning lights can be simple LED's or old fashioned filament lamps.
Lamps tend to fail but are often easier to replace. If using LED's they can be inserted into small sockets, or to use the type already fitted into a simple 12 volt package and mounting bezel. If you decide to use LED warning lights, then preferably choose the easier ways to replace them.
LED's (light emitting diodes) are very reliable and totally shock and sea proof. So if choosing the LED design route; a few pointers. Most LED's use 3 volts although some are as low as 2 volts. Fortunately there are some available for use with 12 volts, (or by adding a resistor).
The legs of the LED's are perfectly good enough to mount into place if a commercial LED socket is used, then the LED's can be simply inserted into the dashboard from the outside plus a little blob of silicone grease or clear glue or grease for waterproofing the hole. The other way to wire in LED's is to push them from below and solder them to a common earth and to the appropriate circuit.
Remember, LED's are one way diodes and they must be connected the correct way around to work.
LED's are also available in a massive selection of colours, sizes and shapes. Always get a few spares as they cost mere pennies.
LED 's for anchor or navigation lights are not as powerful as filament lamps so you will need many more. LED's are always a narrow beam design, so you will need many to make the 360 degrees for an anchor light and quite a few for the other navigation lights. I would recommend at least a dozen white LED's soldered together with a voltage dropper from 12 to 3.5 volts to make a half-decent, 360 degree white anchor light. I would recommend at least a dozen for each red or green navigation light, with a voltage dropper from 12 to 3.0 volts. If using a dozen or more, then you can connect them in series so they act as four to take 12 volts, but if one fails, all four fail.

If you have a yacht without a power source and must rely upon solar or wind power, then always consider LED's for all your needs as they have very low power drain. The modern white LED's can also be used for lighting, but give a narrow frequency band for an un-warming light, but otherwise work perfectly well. By adding plenty of white LED's, the cabin night-time lighting can be reasonable with very small drain on the battery and easily maintained from a small wind turbine, solar panel or drag turbine.
(A Drag Turbine (c) J.Partridge 2004. A pocket sized emergency item I've been making for years; a small propeller generator which is thrown astern when sailing to simply charge up the battery with minimal drag, but originally designed for tidal esturail flows where sunshine is not common. I also make a drag pump for tidal and sailing use - simply a pipe stuck into the bilge and the pump end thrown overboard. Prices start from 30 pounds- email jhpart at btinternet.com for details.)

The dashboard warning lights either work by illuminating red or green when working or in some cases, to go out when in use. Therefore it is vitally important to make sure you get the light to work as needed. Because the lights should be either green for constant safety, or red for immediate warning, then the choice will depend upon its use and wiring. As you may well be motoring without remaining close to the controls, such as gentle fishing, then always add warning buzzers to the oil pressure, water temperature and charging warning lights.

The alternator warning light: This goes out when all is well and the engine runs the alternator to charge the battery.

Voltage gauge: This is an alternative to the alternator light and gives an indication of the voltage on the system. At rest the battery voltage gradually rests back to 12 volts. It may drop below 12 volts if often using a bilge pump or anchor light. When the battery is charging, the voltage will rise up to about 14 volts from a fast running engine. On many slow running diesels, the alternator may not put out much power until the engine revs up a little, and so any cruising with marginal alternators may need to be adjusted to ensure the alternator charges the battery by changing the pulley diameters.
(If chugging away all night with deck lights on a working boat, always check the charging output and be prepared to use a smaller pulley on the alternator or a larger pulley on the engine so that a low revving engine can still supply more power than the deck lights require. Adding an ammeter is also recommended. )
The voltmeter must be connected after the main isolator switch and preferably after the ignition switch. Marking the voltage gauge with 12 and 13.8 volts is recommended. When below 12 volts, it acts as warning.
Most echo sounders and fish finders will also have voltage readouts.

Oil pressure light: Red. There is usually a switch near the oil gallery on the engine, often near the oil pressure pipe. The switch on the engine shorts to earth when the oil pressure gets low. By fitting a warning light to 12 volts, and a wire to the oil pressure switch on the engine, the light will warn of low pressure. It will go out when oil pressure rises to a safe, working level. Only one wire to the sensor. Always add a buzzer.

Oil pressure gauge: This is either a long copper or plastic pipe to a gauge which moves a lever to show pressure. The other version can be a variable resistor and electrical connection to the gauge. Note: Where a copper oil pipe is fitted, it must be allowed to move with the engine on its rubber mounts, but not vibrate too much, so always mount the pipe in foam rubber near the engine and position it tidily to the control panel. A couple of turns or coils in the pipe near the engine helps reduce vibration fracturing problems. Designed properly, it will not fracture and not spill all the engine oil into the bilge.

Water temperature gauge: This is a screw-in thermistor in the engine water gallery and can electrically drive a gauge. The gauge needs 12 volts, earth and a wire to the thermistor. The needle is moved according to the resistance in the thermistor in the engine. A thermistor is simply a temperature dependant variable resistor. Only one wire needed to the thermistor.

Water temperature warning light: This is a light which can act as back up to the water temperature gauge. They are not easy to fit. If you use a heat exchanger or are apt to ignore gauges, then connect a light and / or buzzer which will illuminate when the engine water temperature reaches about 80 to 90 degrees Celsius. This will need a variable resistor and a transistor and variable resistor or LED and variable resistor so they can be adjusted to the particular engine and water temperature thermistor reading.

Fuel gauge: This acts on a low voltage, low current resistor in the fuel tank which varies in resistance according to the position of a lever and float. The fuel gauge has a low current resistor in the tank which changes resistance according to the position of a lever operated by a float in the fuel. The gauge has a middle connection to the float resistor so that the resistance in the fuel tank mirrors the position on the gauge. (Car and motorcycle systems work particularly well and reliably for mere pennies and are easily adapted.) For marine use, always have the fuel sensor arm aligned fore and aft, otherwise it will be moving about too much in high seas. It is assumed the fuel tank will have anti slosh baffles.
An alternative to a remote fuel level gauge is a simple float with a stick in a clear tube which sticks out of the tank, so that it shows a simple, physical indication of fuel in the tank. If you only want it to warn when one quarter full, then a shorter stick can operate a simple switch for a warning light of low fuel level.
Because boats can give fuel gauges a particularly hard time, they can be rather unreliable, so always add sensible modifications to damp the float mechanism or add a sight glass to the fuel tank or include a dip stick.

There are many other gauges and switches, often placed for style or posing purposes, but if there is ample fuel, good engine oil pressure, engine water temperature and battery voltage are good, then the rest is up to the owner.
Don't make a poncy, 'boatie' cabin, all chrome, dials and levers. Always make a sensible working control panel which is reliable and safe at sea.

Other items.
Yachts also need extra items, especially when a motor is considered only for emergencies.
When any digital compass heading or wind speed from a mast head anemometer and perhaps a sea speed sensor (log) are used, then these should be positioned appropriately to be seen with one hand on the tiller and one on the gunwale, from both sides of the hull. At dusk, you may wish the compass light could be a little brighter, plus a dimmer switch to adjust the illumination for very dark night time sailing.
The dimmer should be waterproof, so it's better to have a simple switch to have low lights or a brighter light. This best done with a suitable number of LED's available in red, green, white, blue yellow or a mixture of these to suit your personal night time lighting needs and according to the position on the boat. Never allow white, red or green light to show other than according to international navigation rules.
Any dim lighting system must be tested in the dark, preferably at sea on a dark night, or at least done in a mildly dark room to test your compass illumination needs. I prefer to do this during sea trials, adjusting the illumination for best night time visibility of the horizon on the darkest, mistiest nights. Switching to full illumination can be done when entering glaring, boatie harbours.
For a battery system of night time sailing, it's preferable to have brighter lights for normal use and a secondary set of dimmer lights, often shielded for night time sailing, so your eyes can remain attuned to the open ocean. This only needs the same circuit for all lights, but with an extra wire with the dimmer lights on the third wire and a dimmer switch. The dimmer lights may simply be lower wattage bulbs painted with coloured lacquer, also mounted in the same brighter light fittings. Alternatively, fit some dedicated bright and dim LED's.
If using filament lamps of the same wattage, then simply fit them all with the same earth connection and have a small power resistor in the earth line to turn down the current flow, dimming them all as desired. The dimmer is a variable resistor capable of handling the maximum brightens of all the lights. For example if using six, five-watt lamps, then the dimmer must be able to handle 5x6 = 30 watts, preferably more for a safety margin. Then by turning up the resistance, the lights will dim as required.
An alternative to cabin deckhead lights, is to use car reversing / tail lights with white and red plastic sections, switching between red lights for dark cruising, and white lights as needed. These are not all that neat and can hit the head, so use flush fitting deck head items where possible.
It is better to fit a selection of large red or white LED's for low light level use, especially with a few over the radio, navigation table and cooking areas.
As LED's usually have a small angle of beam, then choose and fit the best lighting options for night time sailing with perfectly attuned eyes.
If wanting to retain good night vision, then get the lighting perfected before leaving harbour.
(My friends have rather neat ultraviolet lamps in their cockpits so they can clearly see their white charts and gauges with no other bright distractions. My marine UV kits start from 25 pounds. Email for details.)

Always site the GPS away from everything else, otherwise you may get false or no readings in your positioning and other items such as fish finders. Therefore keep one side of the boat or cabin for GPS and the other for radio etc.

Laptop computers are ideal for many purposes, including navigation. Computers go wrong: It's what computers do best.
So if you can afford a laptop for your ocean going jaunts, then always buy two. Second hand laptops are under 100 quid, and often do perfectly well for the needs of yachting. Therefore there is no reason why a second one, complete with identical software which is updated weekly for cruising, (or daily for racing) then stored away safely for an excellent method of reliable navigation.
Always include a back up (calibrated) sextant and chronometer set to Greenwich Mean Time, and check you know how to use them by using them - regularly. Then compare with your GPS and other stuff which needs power and may one day let you down. When many large and small scale charts are needed, but no room, then use a compact 12 volt A4 printer and stick the pieces together, using your laptop to print out what is needed. Check for waterproof inks or make a waterproof chart holder or laminate.
Being able to clip a laminated print of a coast line in plain view on the cockpit, with a UV light, enables night sailing unknown waters to be much safer.

If using Long Wave - single side band, then consider fitting an earthing plane of a ring of copper around a plastic hull or a sea plate to ground the system. The backstay of a yacht, when insulated at both ends, makes a superb SSB antenna. No person must be able to touch the antenna when broadcasting, so keep it insulated above head level and well out of the way to prevent electric shock.
Many cities offer open wi-fi connections for mail and internet access, so consider this as an option, get the laptop sorted and also protected with a decent firewall and anti virus.
I can supply complete marine laptop systems - email for details.
If using cell phones (mobiles) the line of sight distance is about 5 miles, but with a bag phone, or an extension kit which boots the power from half a watt to three watts, and putting this on the top of the mast, then a 25 mile range to coastal masts is possible. This can also allow access to the internet without nearing shore.

If lightning is approaching, then make sure you have a damn good earthing system. At least clamp one end of your emergency car jumper leads from the steel mast stays and dangle the other end in the water. Disconnect or unplug all electronics with a master isolation switch or at least make sure they are well protected or militarily 'hardened'.

Once the wiring is done, always check for potential damage.
Damage is not only accidental, but can also be passive. A constantly rocking boat with loose wires is going to abrade the wire and allow eventual corrosion of the inner copper wire. Always restrain the wiring from unwanted movement, using lugs or dabs of silicone sealant to the hull or plastic clips used for telephone and TV aerials in wooden hulls. Replace any steel nails with brass screws, then a dab of paint.
The only flexible part of the wiring should be near the engine which moves on its rubber mounts and any hinged dash board.
Where any wiring may pass though the bilge then it must always be shielded in a plastic casing, - 7 core trailer cable is ideal for double insulation and impervious to most fuels and common solvents. But the ends must be sealed with silicone sealant.
Where wiring goes up the mast, it must be restrained from abrasion and away from any ropes, wires and stays. Therefore always use nylon tie wraps or run inside a mast. If running through a mast, always firmly stick pads of sponge foam or rings of closed cell camping mat around the wire every foot or so, to keep the wiring from rubbing against the inside of the mast to reduce physical abrasion, and those horrible, unwanted clanking noises while at anchor.

Emergency items.
Always have a couple of hand wind up torches (flashlights) kept in a plastic waterproof bag until needed. Spare fuses, a long dual core wire with crocodile clips at each end, and such like, all in a watertight plastic container which is safe and easily accessible. To prevent damage, always pack in foam to protect fuses, torches, lamps and any other items. Always include the tools to replace and repair.
Leaving tools in the garage is not going to be of use on the high seas. - a dedicated set of tools for the boat, which stay with the boat are nigh-on mandatory.
Only a fool uses these and never replaces them back, ready for future emergencies.

The steering position of a fancy motor boat is often a plethora of fancy shiny dials and such like. But instrumentation for engines and boats is usually a sensible selection of dials. This builds up to a need for a large space in the cabin or near the steering position. It may look good for fancy boats or those who need to be impressed for buying machines from boat shows, or want to think their boat is bigger or more clever than it really is. But for real use, a big spread of dials and gauges and lights are NOT always desired nor needed, especially when room on board is at a premium.
The gearbox control can be a neatly hidden, sliding lever down one corner for F-N-A, while the throttle can be a small, almost insignificant rotating thumb dial.
On ocean yachts, it is often necessary to include repeater devices inside the cabin when on auto pilot so that any warnings or changes can be easily seen at all times and reacted to when taking cat-naps or preparing a good meal.

I prefer all controls to be compact and effective with nothing to prove; no ego enhancing crap and leaving plenty of room for the chart, 7x50 binoculars, a cup of tea and perhaps a biscuit.

Alternatives.
Instrumentation for engines and boats is usually available from the manufacturer and may cost daft amounts of money.
I build many and diverse designs, and always revert back to a small selection of excellent alternative display devices for my own use, although for some people, larger items still seem to be preferred.
For example of a very basic, pragmatic approach, a 50 quid after market motorcycle LED screen is not only waterproof, but far cheaper and contains rev counter, speedo, fuel gauge and volt meter etc. They are easily adapted and include adjustments to match accurate readings. The generic device shown here, which is comparatively cheap to buy, has an analogue tacho, digital speedo (log), voltmeter, fuel gauge, overall distance travelled, an individual trip, clock and back light. The overall 'Riding Time' readout is even ideal as a substitute for 'hours run' meter for an engine of a motor boat. Around the bezel are oil and other warning lights and the waterproof operating buttons.
Such devices are not only waterproof and very lightweight, but are compact and run off 12 volts or small batteries which need next to no power and easily powered by a baby solar cell.
For a diesel engine, then the rev counter can be adapted by gluing a magnet to the crankshaft pulley and fitting small pulser or a simple reed switch and a similar device for the speedo reading to give a log in knots.

For yachts with composite masts using integral strain gauges, then the analogue tachometer bar can be used to indicate the strain on the mast, or used for indicating wind speed from an anemometer on the top of the mast.
The speedo counter gives a bright and clear water speed log, while the voltmeter offers alternative solar and wind turbine generation read outs. These LCD screens are also very easy to read in all lights and far neater than a plethora of many tacky gauges.
On very small boats and one man yachts, even the most humble push bike speedo / computer offers more data handling than is needed, and all for under five pounds.
The disadvantage of such devices is that they need electricity, but a back up battery is included to retain the data for a year or more. The push bike devices are even better and ideal for small yachts, as they only need a single cheap button battery for a year of use, and that includes powering the reed switch speedo (log) sensor. Batteries (CR2032) are four for a pound. When a couple of micro solar cells from discarded calculators are added, then such devices are incredibly cheap and totally bomb proof.
For larger yachts, such devices also make excellent repeater units for inside the cabin, to keep an eye on the boat when making lunch or while cat-napping with an autopilot (see appendix).
Having such cheap devices also allows a spare to be carried and 'hot swapped' at a minutes notice - something the most expensive ocean racers rarely seem to have. It is not rocket science.

There is a tendency for power boats to have overly impressive throttles as if they were some form of fertility symbol. Any engine needs just a simple friction throttle lever and a gearbox lever for forwards, neutral and astern. If a Z drive then perhaps some tilt adjustment. Only a racing planing hull needs fast throttle response. For most others, this is not needed, nor really desirable. Many boats have the throttle set for many hours. Therefore very little control leverage indeed is actually needed, and engine controls can be discretely hidden, other than a very simple throttle and an engine stop button. For stopping diesels, then a cable is often needed to pull the fuel pump stop lever.
In heavy seas, a lever is not a very good idea for throttle control, and I consider a simple rotating knob makes a far better throttle control device, especially if out of the way from being nudged by accident. My favourite throttle alternative is a pair of older push bike deraileur gear controls as they are not only small, effective, designed for cables, but also very compact and have adjustable friction control for two engines. Small but perfectly formed. A matched left and right pair are ideal for twin motors.

Other boat stuff.

See also more involved fuel tank requirements and lightning protection on the companion monograph - 'Hulls' - on this website.

Fresh water (drinking water) tanks.
Fresh water tanks must always be meticulously cleaned and maintained, preferably food grade nylon or polythene (polyethylene). They should ideally be removable for inspection and regular cleaning. Drain each season and thoroughly remove debris, sterilised with water additive such as a little chlorine, then dried out, ready for the next season.
When building such tanks into a hull, they should be lined with epoxy. Also include access hatches for full cleaning by hand. I like to line integral hull fresh water tanks with both aluminium foil and epoxy.
Where possible, consider a water maker, driven from the engine or using 12 volt motor to ensure fresh drinking water. PUR watermakers offer a fine range of options. Manual desalinators are also available and should be used as a back up, plus a small one for the life raft or grab bag.

Water cooling pump.
Because salt water will corrode an engine, most engines are either marinised or use an intermediate cooling system.

Marinised engines are designed to use sea water in the engine for cooling, but the internals are designed to ensure the salt water does not corrode the internals. The alloy parts of the engine are anodised internally while all other parts are made from stainless or are coated with protective layers. Thus the engine can pump sea water around the cooling channels with no problems other than a screen to preclude debris or seaweed etc.
Because the sea water is at a much lower temperature, then little coolant flow is needed, (unlike a car which has a limited amount of hot coolant and needs a radiator and high flow to keep it cool). Therefore a marinised engine need only pump low volumes of water and this is done to exit via the exhaust to both cool the exhaust and to ensure the user can see that the water flow is reliable. Although the sea inlet is carefully chosen, the motor can still drain down when beached, so the water pump will be designed to purge air from the water channels and the exit water is therefore often at a high point in the engine.
If such an engine pump should fail then it will ether block the sea water flow or allow free water flow. If free to flow then sea water can be poured into the engine from a high point, ensuring it can flow to cool the engine. If the sea water pump is blocked, then only use the engine for short times and keep topping up the engine coolant system when needed to get you home.
Always carry at least two buckets onboard. As the metal or plastic handles often fail, then replace the handles with rope.

See also more involved water cooling, a simple DIY intercooler, sea valve inlets and anti corrosion requirements on the companion monograph on this website.

Intermediate cooling systems.
These are often used on car engines with a marine gearbox bolted on the end. (You can use a car gearbox if you wish, and setting the propeller to work best with 1st gear and reverse, as they are similar in revs - but it is better to fit a marine gearbox with effectively direct drive or 2:1 or 3:1 reduction is the most reliable).
The cooling system of a car engine is designed to run with fresh water and antifreeze, with the car engine water pump doing its own thing with the sealed fresh water in the engine. The heat transfer to the sea water will therefore need an extra coolant pump to pump sea water from the sea and across an intercooler which then cools the separate engine coolant. The intercooler is usually just a set of alloy-bronze or stainless pipes in a waterjacket, so the engine heat can transfer to the sea. The sea water pump is normally driven from the engine and as such, the belt or chain drive will need regular maintenance. Once again, because the sea is always much cooler than the engine, the sea coolant flow will be less than a normal car engine coolant flow. The impellers of sea pumps are often made of hard rubber and a spare must always be carried, along with the tools to replace it.
Therefore the engine side of the intercooler will be passing high flows of car coolant whereas the sea pump will be passing lower volumes of much cooler sea water. If the engine cooling water is about 80 degrees, and sea water is about 10 degrees, then only about one eighth of the amount of sea water is needed to dissipate the heat.
In emergency, the engine can be cooled with sea water to get home in an emergency, but must later be flushed fully to prevent corrosion in the engine.)
Screen.
As sea water is not guaranteed pure, debris can accumulate in the system so a screen is placed between the inlet hole and the heat exchanger. This can get clogged and will need to be cleaned. To do this when afloat, it must be accessible with minimal hassle, so the removable screen is used. Either a quick removal, with replacing the top before to much water enters the bilge or in a compartment which has sides above water level. I prefer a simple quick removable screen, which can be replaced as a cylindrical perforated stainless steel tube inside a larger T piece with easily removed cap which takes just a few seconds to replace. For larger systems, then than inspection plate can be added, such as a piece of Polycarbonate riot shield set close to the screen or set in the screw lid. Always carry perfectly shaped wooden bungs very close nearby for when things go wrong or of you want to work at leisure.
An engine water temperature gauge is nigh-on mandatory and is very easy to fit. Especially recommended where seaweed is prevalent.

Hydraulic pumps and motors.
Working boats often use a hydraulic motor to haul in nets and pots or small cranes for semi rigid units.
The power unit is a simple hydraulic pump driven from the end of the crankshaft, via a hydraulic valve block to control a hydraulic winch motor. Normally a sealed system connected by two pipes. If leakage is noticed, make a running repair, then top up the system with specialist oil when the engine is stopped.
Hydraulic systems can also be used in larger boats for weighing anchors, steering, cranes or other equipment.
(Safety systems such as deploying lifeboats should always be done by gravity or other fail safe systems, although general purpose boats on ships can often be lifted back into position using hydraulic motors, often driven by the ancillary engine or a generator.)
The hydraulic car jacks and lifts found in smaller garages can easily be modified to act as hydraulic davits and cranes, needing only a hand pump to operate.

Engine maintenance and preservation.

The point to note here is that many engines never properly get 'winterised' and likewise boats don't need much of this crap either, unless you only use your boat for a few weeks each summer.
For real boat owners, do it yourself.

'Winterising' outboard motors.
As most small outboards are petrol, then the problems are related to fuel lacquering up the carb jets in winter, salt water corrosion in the cooling system and condensation in the electrics causing corrosion.
If a four stoke, give the engine an oil change and replace the oil filter before the last run of the season so that any acid in the old oil does not damage the internals during winter.
Remove the fuel: Drain or syphon the fuel then run the engine until it dies. If going for a last run of the season, always carry spare fuel in the boat.
If you can run the motor in fresh water, use a garden hose to flush through all the waterways and if the motor is not too large, then mount on a garden gate and run using fresh water through the water-cooling inlet for ten seconds to flush through any salt water.
If the carbs have drain plugs, then remove and drain the carbs as this prevents lacquering in the small brass jets. If fuel injection, then the last run should include some fuel injection cleaner additive to the fuel before storage.
Drain the fuel in the tank and carburettor and replace the fuel drain screw. If leaving fuel in the tank, remove the drain screw, so that any leakage can drain away and evaporate rather than block the carbs.
Fuel filter (always recommended), remove and inspect. If a cheap disposable see-through item, simply replace or reverse flush through with spare fuel. If a cartridge filter, then remove to allow fuel to evaporate, then replace with new after all the fuel has been drained. Cut open the old fuel filter and examine if you suspect problems.
Maintenance spray all the electrics and any sensors, switches, cables and such like.
Remove the air filter and inspect for dirt and a small, quick squirt of maintenance spray into the inlet tracts. Replace the old filter but budget for a new filter in the summer. Cover the air inlet with a plastic bag.
Finally unscrew the spark plugs and check their condition. If after the normal run, they are pale brown, all is well, but check with the owners manual. Squirt some maintenance spray (or two stroke oil) in the spark plug holes, and give a couple of slow turns by hand. Replace the spark plugs. If the plugs look doubtful, buy a spare set and leave them in their boxes until the summer.
Store in a dry place. If not, then wait for a hot day, then cover in a large bin liner. If you have silica moisture absorber, then place the silica in the oven to dry out, as per instructions, then insert the absorber bags inside the outboard motor covers and if any spare, in the (old) air filter, up the exhaust and coolant ducts. Then tape up the orifices.
Never store a motor in a damp place, as it's far better to allow free air in a damp environment, as this causes less condensation.
Grease the propeller, transom mount threads and such like. If a remote linkage, then service this too.

Recommissioning outboard motors.
Replace any carburettor drains and fill the fuel tanks with fresh fuel.
In the summer, remove the spark plugs and any moisture absorber. Replace the air filter if it shows signs of excess dirt. (Dirt in an old air filter helps keep moisture out during the winter.) If a toggle start, turn the engine over by hand a few times to check the engine turns over freely and to blow out any preserving oil in the spark plug holes. Clean the old plugs in fuel, replace then run the engine for a minute. If it won't start, check for sparks and use the new spark plugs. After running, fit the new spark plugs.
On fuel injection systems it may take a few seconds for the fuel to reach running pressure, so wait ten seconds before starting so any electric fuel pump can prime the system before starting the motor. If a remote fuel tank, then pressurise if required.
Run the engine in the sea (or pond or large dustbin filed with water ) to test for five minutes and check running temperatures. Do not do this near seaweed or other means of blocking the inlet.

If you did not drain the carb, an it is clogged, then remove the float, fill the float bowl with nail varnish remover or acetone and leave overnight to dissolve any lacquer in the jets. Clean, reassemble and check again. If the tick over jet is blocked, use the wire from a wire brush to clean it out. If very dirty, use a push bike pump with small nozzle attachment to blow through all orifices.

'Winterising' inboard engines.
Diesels.
Diesels do not need much maintenance as the fuel is a natural, oily preservative.
The injectors and pumps will remain flooded in the diesel oil and thus remain in perfect working condition unless there is water or other contaminants in the fuel or leakage in the low pressure side of the system. It is worth giving the diesel a dozen slow turns by hand (use the decompressor lever) to fill the combustion chambers with excess diesel oil to keep the rings and nozzles lubricated over winter.
The fuel tank should be checked for water or sediments in the base. If in doubt about sediment or water in the fuel, flush the fuel tank system, including the pipework, clean and fit a new fuel filter and run the engine to purge the fuel system. Always fit a new fuel filter every year and more if demanded by the manufacturer. The diesel fuel can be left in the tank.
If suspecting fuel leaks, then empty the tank over winter and tape over all vents to prevent condensation. Use yellow vinyl tape and use a tie wrap to prevent them falling off as the adhesive will break down with the vapour.
Do an oil change and a new oil filter before the last run. This leaves oil with no acids or contaminants in the engine, so damage is less. The new oil may absorb some moisture over winter if the engine is open to the atmosphere, so cover intakes with a plastic bag and some tape to prevent air contamination. But any moisture absorbed into the oil over the winter will burn off in the first run of the new season.
If leaving fresh water in the engine, always flush through with fresh water and add new antifreeze before making a final run of the season to warm through. (If in Arctic lands, drain down for winter. Try to beach the craft to also drain any sea water ways which may freeze.) The problem with cooling water which freezes is that it expands and can easily crack crankcases. Although sea water freezes at a lower temperature, it still can damage the engine, cooling system and pipework. It the boat engine also supplies warm cooling water to internal heaters, then these too must be drained down or filled with suitable antifreeze by running the full heating system with fresh coolant with fresh antifreeze suitable for the minimum temperatures to be expected.
Replace fresh water coolant and add antifreeze as recommended by the manufacturer according to the ambient winter temperatures.
Finally make a complete physical check of the engine mounts, pipe lines, wiring and such like. Make a list of spares and any tools needed. Clean and check all engine mounts, shaft rubber joints, vee belts and seals.
Clean the bilge scrupulously as this will indicate any other problems, both now and when returning.

Recommissioning.
Remove all temporary covers, vents and such like. Turn the engine over by hand to check all is well. Start the engine by hand if the battery is not up to the job and budget for a larger solar panel or wind generator.
Check coolant levels, oil levels, top up as needed. Check fuel systems then start the engine.
Check for fuel and coolant leaks. Check oil pressure, temperature and electric charging. After warming through, stop the engine, adjust Vee belts and check and adjust valve clearances. Check stern tube leakage.

Winterising Petrol.
Petrol motors have carburettors which, as the fuel evaporates over the winter, can leave a lacquer deposit in carburettor jets and block them. It can be cleaned out with acetone, (or nail varnish remover), but this can damage other components, such as delicate rubber seals. So it's better to not to let this happen in the first place. Therefore the carburettors are drained so the lacquer does not occur in the first place.
To aid reliability, use petrol cleaning additive, a new fuel filter, an oil change and new oil filter on the last run.
If you can run the motor in fresh water, do so, perhaps in an out going tide high in an estuary.
Flush any fresh water cooling system and add antifreeze. If suspecting leaks, then empty the fuel tank over winter and tape over all vents with yellow vinyl tape and use a tie wrap to prevent it falling off.
Drain or siphon out the fuel. If going for a last run of the season, run down the fuel tanks and always carry spare fuel in the boat. If suspecting dirty fuel or tanks, after inspecting the fuel filter, empty the tanks, allow to dry and clean them or slosh with clean fuel and syphon any debris from the bottom. Dirty fuel can be filtered through a cloth for re use.
If a fuel filter, then remove and inspect. If a cheap disposable see-through item, simply replace. If a cartridge filter, then remove to allow fuel to evaporate, then replace with new. If the carbs have drain plugs, then remove and drain the carbs as this prevents lacquering in the small brass jets.
If suspecting a leaky fuel tap, then leave the drain off and secure the plug close by in a cloth bag or old sock. The removed drain will ensure the carb does not fill from a leaky tap.
If fuel injection, then the last run should include some fuel injection cleaner additive to the fuel before storage.
Maintenance spray all the electrics and any switches, cables and such like.
Remove the air filter and inspect for dirt and a small, quick squirt of maintenance spray into the inlet tracts. Replace the old air filter but budget for a new filter in the summer.
Finally unscrew the spark plugs and check their condition. If after the normal run, they are pale brown, all is well, but check with the owners manual. If the plugs look doubtful, buy a spare set and leave them in their boxes until the summer. Squirt of maintenance spray or two stoke oil into the plug holes followed by a couple of turns of the crank by hand. Replace the spark plugs.

Clean and check the bilges.
If a separate engine room, make sure the bulkheads are in good condition and any external vets are closed just after a warm run. If not, or a smaller boat, then wait for a hot day, then cover the engine in a large bin liner. If you have silica moisture absorber, then place the silica into the oven to dry out, as per instructions, then insert the absorber bags in the motor covers and if any spare, up the exhaust. Seal the exhaust and such outward vents with bright yellow gaffer tape which should survive most of the winter, yet peel off if you forget when starting again in the summer. If out of the water, always flush the sea water inlet with fresh water. If in the sea then use a soft foam bung to keep it from clogging or unwanted visitors.
Never seal a motor in a damp place, as it's better to allow free air in a damp environment as this does not cause condensation. It will depend upon the latitude, the storage and winter conditions.
(If in Arctic lands, drain down for winter. Always beach the craft to drain any sea water ways which may freeze.)
The fuel tank should be checked for water or other sediments in the base, so open the hatch and use a siphon to remove anything unwanted in the base of the fuel tank. The petrol tank can be left empty and vented or filled right up to prevent condensation occurring. Leaving it empty or mostly empty prevent problems with any fuel leaks. Lightly fitting cloth and yellow plugs or tape over the vents will be safer.

Petrol fuel injection systems do not have carburettors and simply have electrically operated valves squirting fuel from a high pressure fuel rail, unfortunately the injectors can suffer from lack of use or if the petrol leaves a lacquer. Although cleaning is straight forward on a test rig, it is best to ensure the last run of fuel has injector cleaner and preservative in the fuel so the high pressure rail does no harm to the injectors. Likewise the fine nozzles are also prone to corrosion in the combustion chambers, so this should be given a squirt of maintenance spray to prevent any damage over the winter. The engine should be run during the last run with some injection cleaner or preservative additive. Always give a good spray of maintenance spray over the electrical connections, so pull off the rubbers and if there is any moisture, allow to dry then spray and reseal. Check all sealing rubbers are not corroded or damaged. Likewise check the ignition wiring.
Finally make a complete physical clean and check of the engine mounts, pipe lines, wiring and such like.

Recommissioning petrol.
Remove the spark plus and any moisture absorber and taped over vents. Remove any sea water inlet tape or bung. Turn the engine over by hand a few times to blow out any oil out of the spark plug holes.
Check coolant levels, oil level, fuel. Drain any condensate from fuel tanks.
Clean the old plugs in fuel, dry them and refit, squirt a few drops of fuel in the spark plug holes and run the engine. If the engine won't start, then use the new spark plugs. After running, fit new spark plugs. Replace the air filter if it shows signs of excess dirt. (There is no point fitting a new air filter before storage, as a clogged filter is more likely to protect from dirt.)
On fuel injection systems, it may take a few seconds for the fuel to reach running pressure, so wait ten seconds so the electric fuel pump primes the system before starting the engine. Any suspect injectors can be easily checked with an engineers stethoscope while running.
Run the engine in the sea to test for five minutes and check running temperatures. Do not do this near seaweed or other means of blocking the inlet. Check oil pressure, temperature and electric charging. Stop the engines, and adjust Vee belts and valve clearances.

As can be seen, winterising is not difficult. A warm run, an oil change and filter, plus an hours work, a roll of yellow duct tape, a can of maintenance spray, perhaps a spark plug spanner is all that's needed. Do it.

Gearboxes.
Gearboxes are often only checked occasionally for leaks of the seals and of the oil level. If you have nasty noises, then drain and check the oil and the drain plug for metallic debris. A magnetic drain plug is recommended.
Adjust the control cable or levers as needed by the manual. Change the oil and grease linkages as needed before winter storage. Clean and inspect any rubber drive shaft coupling.

Rudders.
Check for damage, sticking pulleys, wear in cables, sloppiness and fouling. Repair as needed. Fully grease all pivots and remote linkages before storing. If greasing is a problem, then you may wish to carefully drill lubrication holes in the pivot bosses and tap threads to take grease nipples, then pump fully until the grease exits the bushes. A simple hand grease pump should suffice all but the largest boats.
If you are happy to do so, then drill the boss, then turn the rudder to check the actual depth of the steering shaft. Now insert the drill bit into the chuck so it will only dill half a millimetre into the shaft, place in the hole and slowly turn the rudder full movement to mill a grease slot in the rudder shaft which will allow grease to penetrate further. Tap and fit a basic grease nipple or screw greaser. Ideally you should always remove the shaft and file decent grease slots, but as some working boats rarely get out of the water, and most boaties don't bother, then this is a good bodge for improved reliability.

Props and shafts.
If the boat remains in water, use a buoyancy aid and safety rope, climb overboard then inspect by hand or with snorkel and goggles if conditions permit. This may need sailing to a suitable spot off a safe bathing beach in a clear, safe and shallow anchorage with few waves. The seas always take longer to cool than ambient air temperature, so swimming in October is perfectly acceptable for most people in the northern hemisphere. (I do.) Never block swimming areas.
If the boat is out of water, make a close physical check of the rudder mounts and propeller.
Alternatively beach on a moderate tide on gravel and wait until low tide. (If you chose the wrong tide, you may be stuck for a month.)
Inspect the shaft for imbalance by turning the propeller and looking for any misalignment.
Check for any wear on any A frames if fitted. Check any lubrication works correctly and purge any stern glands with fresh grease, but ensure it does not damage any seals. Where the stern gland is sealed with waxed packing, then remove and fit new packing as needed, or add a another ring of new packing and grease well, so there is plenty of adjustment in the stern gland for the following season.
The propeller leading edge should be smooth. If there are any dents, smooth with fine sand paper or waterproof abrasive paper, but do not remove any metal, - keep the blades as close to manufacturers original as possible.
Check security of the prop nuts, rudder lower pivots, shear pins and such like. If in any doubt, always prepare to replace with new or to recondition them. (See also the Hulls monograph props and shafts.)
When adjusting stern packing, the seal should allow a drop a minute, any tighter and it can 'burn' the packing on the prop shaft.

Finally clean all components, grease pivots and wax polish or special anti fouling paint any areas which may be prone to barnacles or other problems during winter.
Caulk all hull, deck and cabin joins and seams before painting.

Winterising batteries.
The best way to look after a battery is to keep it clean, ensure any acid level is filled with distilled water to the correct level and regularly charged. This usually needs a solar panel or a wind turbine.
If taking the battery off the boat, then use a weekly charge and occasional discharge. Never allow the battery to discharge below 10 volts.
See above, and also my batteries webpage.
Before replacing a suspect battery on a boat, make a simple check using a car headlight and see how long it takes to run down to 10 volts. Do the same, but wait a week after charging, before testing. If the battery capacity (amps x hours) is acceptable then replace on the boat. Otherwise fit a new battery. If a car headlight is 60 watts, and the light stays illuminated for 4 hours then the battery has an approximate capacity of 4x60 = 240 Amp Hours. Read the battery label and see if this about acceptable with the original specification on the label. Two thirds or more of the manufacturers rating is acceptable.

If you leave the battery on the boat because it must work the bilge pump, then disconnect the main supply cable and only connect the battery to the bilge pump and to any solar cell or wind turbine. Always make a manual check that the bilge pump is working on automatic, by moving the level float switch by hand, or by throwing a couple of buckets of water in the bilge, just before leaving the boat.

Other boat stuff.

Secondary batteries.
Secondary batteries are often needed such as for fridges, winches and other systems which need to be maintained, but they must never interfere with the anchor light or bilge pump supply. Therefore a secondary battery is recommended to power any heavy drain, but not important components.
The secondary battery can also be charged up by the motor or solar panel or wind turbine and still ensure the critical systems remain safe. By using a diode, both can be charged, (using separate solar cells), the secondary battery being connected to a fridge or whatever, but never being allowed to drain the primary battery.
When the voltage in the secondary battery drops below 10 volts, a calibrated relay can switch to take some of the primary battery power for the anchor light and bilge pump, but never take power from the primary battery for anything else while the main isolator switch is disconnected.

If both batteries are the same size and connections (good design) then always replace the primary with the new battery and put the older battery as secondary. - If the main battery fails, the other can be used to start the engine and return safely. If the life span of the batteries is four years, then by replacing one every two years will give a safety margin, rather than expecting both to fail in the same season, perhaps on the same voyage.

Power to fridges, cookers and winches should always be from a secondary battery or only when the engine is running. If you use a single battery without the engine running, then you may drain the one battery and not be able to start the engine, so a battery safety warning buzzer is highly recommended. The primary battery must never near a state which will prevent the engine from starting or the bilge from pumping.
If the engine has an emergency hand crank starter, then always start the engine by this method at the start of every season, so you can still get safely back to harbour when all else fails.

Dinghies, wheels and paddles.

No one likes the hassle of trailers. - Everyone hates the prat boaties in their daft 4x4's taking up double the parking space with their massive 'bimboy truck' and trailer.

Quite often there is no easy access mooring. Non inflatable dinghies for reaching a mooring are often stolen so always make sure it's padlocked to some secure fitting.
Where there is no secure dinghy park, then the dinghy may need to be transportable by car or similar to the boat or to use a minimalist design. The inflatable dinghy with paddles is common or with a Seagull. Electric outboards are prone to not being charged up when needed or not strong enough for some tides. It is often easier to have a fixed electric drive in the dinghy and simply carry a big battery, but always include paddles.
The simplest dinghy is a single seat platform but this is not wise. It is recommended to have dual seating plus some cargo space, otherwise there can only be one person on board, or a lot of long string work.
The displacement and thus the physical size of a dinghy for two persons plus some luggage is not much. Such a dinghy is easily moved by one person, with a wheel or pair of wheels at the bow or stern so it can be wheeled to storage or the car roof to make life easy for all.
Where a dinghy is not possible, then a two person, collapsible mini catamaran or a frame across a pair of small canoes can do the job. A simple folding or easy assessable catamaran platform is useful and allows easy stability in relatively calm estuaries and a Seagull across the rear plank.
Where a dinghy is needed in waves, such as coastal voyages, then a single hull is often better and is the most common option.
If you look at the size and shape of the typical car roof, then it may be possible to make a dinghy which will fit neatly over the car roof, but the problems will be in any height restricted parking zone when it may need the dinghy to be removed before entry if you have a tall vehicle. To make a car roof dinghy, it's imperative to make a stable hull, so copy the water profile of a similar dinghy. Then cover your car roof with thick plastic and space off the hull to a suitable gunwale distance, so the car doors can be opened, then built up the edges. Now the roof rack can be fitted, shaped or modified to retain the hull. This can be done with a couple of lugs on one side of the rack, so the hull slots into place, and a simple pair of catches on the other side. The internal seating and buoyancy compartments are now made. The remaining space on the roof rack can now be made into storage areas for bulky, lightweight items such as folding oars and buoyancy aids.

Life Jackets. - See Lifejacket webpage.
Survival swimming. - See swimming webpage.
Solar stills. - See solar stills webpage.

Boats re-wired, re-engineered and modified by appointment. email for info.

Enjoy your holiday, but don't be like the many Plymouth 'boaties' who mess up the holidays of so many others.

Make a better Britain.

If you don't think an MP and staff and freebies are worth 125,000 pounds of our taxes each year, then don't vote for them.- Vote for honest people, or spoil your vote to show your disgust.

Always try to improve society rather than just take from it. Until then, lawyer stuff. Copying or duplication of this material is prohibited without written permission of the author. The content is for information only. No responsibility is accepted for any damage or any injury caused by the above information. Errors and omissions excepted. No-one should try anything in the politically correct world without reasonable abilities and know that injuries and lawyers can ensue from the materials, tools and from testing. Have a nice (lawyer free) day.

Copyright (C) J.Partridge. 1999. 2003. 2005. 2007.