The M class subs

The idea was brilliant. They would build a huge gun, which could travel underwater until it was within range of enemy ships or troops on shore, and it would then pour devastating fire on such targets without doing more than showing the tip of the gun's muzzle above the surface And if it wasn't technically possible to produce a self-propelled underwater gun in 1916, there was nothing to stop them mounting a huge gun from a battleship on to a submarine - and then all the rest would follow. 
To carry out this idea, the "M" class of submarines was created. They were unique; there was no doubt about that. The first one, M1 was not purpose built. She had been laid down in the Vickers yard at Barrow as the K-18, but was altered to take a 12-inch gun from one of the Edward VII class of battleships. It was a colossal gun to fit on a submarine. In all the navies of the world at that time the largest gun on any submarine was a five-inch. Mounting a 12-inch gun on the M-1 caused all sorts of problems, but they were not allowed to stop the work. Pushing the idea along was the First Sea Lord, Lord "Jackie" Fisher, who created the Dreadnoughts, was a great sponsor of heavy guns and an enthusiastic champion of submarines too. 
But even with his push behind it, work on the four subs of the M-class went along slowly. The new submarines were 300 feet long with a surface speed of over 15 knots and nearly 10 submerged. The M-1 and M-2 were ordered from Vickers, the M-3 and M-4 from Armstrong’s. The techniques for using them were worked out as the building went along. The original idea had to be modified. The plan was now that the gun would be loaded on the surface and was to be laid for high-elevation shooting. Once the gun had been loaded the submarine was to be taken down to a little over 12 feet so that the muzzle was left just poking out of the water. The muzzle also had a bead sight on it so that the gunnery officer while looking through the periscope could aim and fire while the boat was running submerged. It all sounded superb and was certainly guaranteed to give the Germans a surprise when was used. There was only one drawback - to reload the submarine had to surface. After the M-1 was launched various problems with the seals around the gun caused so many delays in getting her into service that the war was over before she could fire a shot in anger and M-2 and M3 were not completed until 1920. M-4s contract was cancelled. M-1 was put into reserve as part of the Fifth Submarine Flotilla attached to HMS Dolphin. By now they had worked out how to use the 60-ton gun. It was loaded, and then the submarine submerged and approached the target, sighting through the periscope. When "on target" the M-1 would surface enough to clear the gun, fire and submerge again. The "pop-up process" took 25 seconds and another 15 were needed to fire, close the muzzle, and dive. However, all did not always go according to plan. Sometimes water got into the muzzle and the M-1 had been known, as a result of seawater in the barrel, to blow off several feet of gun at the muzzle end. 
In early November 1925, a major submarine exercise was held in the Channel of the coast of Devon. M-1 took part, as did the submarines H-22, H-29, H-30, H-34, the submarine depot ship Maidstone and the submarine tender Alecto. On Friday, the 13th of November, M-1 did not respond to radio calls, nor did she report herself. There was no sign of her despite a huge search, which started at once. Any and every contact in the area where she was last known to be was dived. A German deep diving salvage company using an articulated armoured diving suit volunteered to help the Navy diving teams, and their chief diver Otto Kraft went down to over 250 feet on several occasions, including night dives, but found nothing. The Navy teams had no better luck, but the search went on. 
First clue to the fate of the M-1 came when the Swedish steamer Vidar, a 2,159-ton merchantman was put into dry dock at Stockholm when she completed her voyage. This was done to check damage that Captain Anell of the Vidar felt he might have surfaced after striking a submerged object at about 8 pm on November 12 when in the approximate position of 49:59:00 N; 03:55: 00 W. The area and the date make it almost certain that the Vidar struck the M-1 in the dark of that November evening. Dry-docking the Vidar proved it – her bow close to her keel was badly bent, plating damaged and several rivets knocked out. More important, the traces of grey paint around the damage exactly matched that of the missing submarine. So it was no surprise when, on December 2, 1925, the Admiralty announced: "Diving operations in connection with the submarine M-2 have been discontinued as no positive results have been obtained. It is not considered necessary to prolong the search as the cause of her loss has been so fully established". There the matter rested. And as the years passed M-1 and her crew of 69 were largely forgotten, except for those who still mourned. Nobody knew exactly where she was. In 1967, the M-1 was brought dramatically back into the news when Captain Silas Oates, of the 134-ton salvage ship, Comrades, announced that he had found the long-lost submarine. He was searching for sunken ships somewhere off Start Point when he found a likely contact. Captain Oates put down one of his divers - 28-year-old Frank Charles - to investigate. Charles reached the seabed at 150 feet in poor visibility and finned slowly forwards. Sure enough a great shape loomed up out of the murk and at first Frank Charles thought it was an old steamer. But when he got closer he knew he was looking at an enormous submarine. "She is sitting more or less level on a bottom of sand and shale," he reported later, "and she is covered with barnacle growth. But as I swam along her side I could make out the letter 'M' quite distinctly. Alongside it was a number that could be a '1', though it was difficult to make out. She looks enormous, a very unusual design for a submarine. There was this great tube thing up front, which I couldn't make out. But now I've seen a photograph of the M-1, I am completely satisfied that it is her and that it was probably her gun I was looking at. Some of the plating forward appears to be missing." Captain Oates was confident that he had found the M-1 and that she was undamaged enough to be brought up by pumping compressed air into her And some naval historians thought the M-1 should be raised to complete our knowledge of her class The Royal Navy, however, thought differently. She was a war grave (see publisher's note at front for details of the Military Remains Act which a lies in this case and should stay undisturbed. 
Did Frank Charles really find the M-1? One man who thinks not is wreck researcher and diver Richard Lam, one of a team who are sure they have found it in a different position - 11 miles off Start Point in 235 feet of water. Dick Lam established the rough position by research into the course of the Vidar and the Admiralty enquiry of the time. Then using a magnetometer in that area, the team got a number of good contacts. One of them was the M-1, and they confirmed this by the use of a remotely controlled undersea vehicle with cameras aboard. This showed that the submarine was intact with the gun in position. The M-1 had only been cold in her seabed grave for six years when it all happened again, - to her sister ship, the M-2. The first Admiralty announcement came on the night of January 26, 1932. It read: "News has been received this evening that Submarine M-2 dived at about 10.30 this incoming off Portland, and since then no further communication has been received from her. Destroyers and submarines from Portland are searching the area in which she was last known to be, and every endeavour is being made to establish communication with her." M-2, like M-1, was unique. Just like her sister ship, she was built to carry a huge 12-inch gun. She too had been laid down in 1916, but was not completed until 1920. In 1927, the gun, following another brilliant idea, was removed. In the space that used to be taken up by the gun mounting, a hangar for a small seaplane, the Parnall Pixie was installed. The Pixie's wings folded for stowage in the hangar. The idea was brilliant and met with instant international recognition that it gave submarines an entirely new dimension. America, as well as many other countries, was quick to recognise the potential and started experiments along exactly similar lines. But the M-2 was well ahead and operational long before overseas experiments were complete. 
The seaplane, one of the smallest two-seaters in the world at that time, was launched by catapult off a runway on the submarine's deck. When the plane returned to the submarine, it landed nearby and then was hoisted on board and into its hangar by a special small crane. Because of the plane, the M-2 became known as the first undersea aircraft carrier in the world. Some holidaymakers at Gosport in 1930 had good cause to know this the little seaplane, which had just taken off from the submarine, stalled and crashed on the beach near them. Fortunately no on was hurt. The M-2s crew were very proud of the speed with which they could launch the little floatplane. They became extremely fast at rising to periscope depth, checking around for enemy ships, surfacing, opening the hangar doors, and catapulting the plane off. They were constantly trying to beat their own record. 
On January 26, 1932 M-2 left Portland Harbour for routine exercises, there was no reason to think that this day would be any different from other exercise days with the "enemy" being just another group of Navy ships. The M-2 was considered safe and seaworthy. True, she had been badly battered in a gale in November 1929, when on a voyage from Portsmouth to Portland, and her bridge and conning tower had been damaged. But that damage had been repaired long ago. The fact that the submarine had survived on the surface in such appalling weather had given the crew even more confidence in her. Not that the sea off Portland on that January day in 1932 was anything else but calm. At just a few moments after 9 am the M-2 set off for West Bay to the West of Portland Bill. There was a little fog about, but nothing to cause any problems. The only thing that was really different about this exercise was that M-2 was to practice alone at first before joining combined exercises with submarines L-67 and L-71 from Portsmouth. The M-2 would not only be exercising with her aircraft, but with the three-inch "disappearing" gun, her two Lewis guns, and with practice torpedoes for her four 18-inch bow tubes. 
For a while all went well. M-2 kept in touch with her parent ship, HMS Titania, and at 10.11 am her captain, Lieutenant-Commander JD de M. Leathes, signalled: "I am going to dive". On board Titania the wireless operators were busy with other submarines going out. So it was not until one wireless operator reported that he could not establish contact with M-2 that any anxiety was felt. But even then it was felt that this was probably only a communications problem. When, however, the submarine failed to return to Portland Harbour (she was due at 4.15 p.m.), a full alarm was raised. Soon the whole area knew about it. Men in theatres and cinemas were recalled and ordered to report to their ships. Cars and coaches were sent from Portland to Weymouth to round them up and hurry them back to base. Managers of cinemas interrupted performances to go on stage and make the recall announcements. Police called at private houses of naval men to tell them of the recall. A number of officers taking part in a dress rehearsal of an amateur dramatic show at Weymouth Pavilion were recalled by police and rushed to their without even bothering to change. By 9 pm - the full alarm had been given just before eight o'clock - some five hundred men had got back to their ships, and they sailed shortly afterwards. 
But action had been taken even earlier than this. By 5.30 - an hour and fifteen minutes after M-2 had failed to return to harbour - HMS Salmon, Torrid, Thruster and Rowena, all destroyers, had sailed. Two submarines, H-44 and H-49, followed at 7 pm, and then more surface ships, carrying the men recalled from the surrounding areas, at a few minutes after 9 pm. Even if the submarine had failed to surface there were some grounds for hope that some men could still escape. The M-2 had enough air to remain under water for 48 hours. In addition, she carried the latest life-saving equipment. In this case that meant the new Davis Escape Apparatus. The Davis equipment had already proved its worth. Only in June of the year before, HMS Poseidon had sunk in collision off the coast of China. The total death roll had been 20, but for the first time in naval history men had escaped from the sunken submarine by using the Davis equipment. 
So there was still a chance for the men of the M-2. Just after midnight the Admiralty announced that a contact had been made: "An object, presumed to be submarine M-2, has been located three miles west of Portland Bill, in 17 fathoms, on a sandy bottom. Salvage craft and divers have been sent from Portsmouth to this position with the utmost despatch." HMS Sabre, a destroyer, carrying divers "specially trained for deep-sea work in connection with submarines" set out from Portsmouth and sped at 25 knots to the scene. Sabre was expected to arrive at the contact point at about 2 am. Two submarine salvage ships left shortly after her, but with there slower speed would not be at the scene of operations before dawn. 
In the meantime the newspapers had contacted Mr R. H. Davis (later to become Sir Robert), inventor of the Davis Escape Apparatus, for his views on the chances of the crew of M-2, which the Admiralty now said consisted of seven officers and 53 men, including two members of the Royal Air Force. Mr Davis was hopeful. "Ibere is no need to abandon hope at all," he said. "The submarine might easily remain under water for 48 hours or even more, and then rise again to the surface. The officers would make every effort to remedy any defect in the vessel's machinery and would not abandon their vessel until every hope was gone. Even then the officers and men would have every chance of escape by means of my apparatus." 
Despite these hopeful thoughts, by the afternoon of Wednesday, January 27, Portsmouth, where 14 of the M-2 crew had their homes, was a city of mourning again - telegrams had been sent to the relatives of all members of the crew. They read: "Regret to inform you that your husband (or son) is missing and feared drowned in submarine M-2, believed sunk of Portland on Tuesday". One of the families who got such a telegram was that of Able Seaman Thomas Morris, who was 25. His wife lived with three young children in Ermine Road, Lewisham, London, and she had been looking forward to her husband leaving the submarine service in a month's time when he completed his 12 years' service with the Navy. The telegram was an even greater shock because Able Seaman Morris had been a survivor of the Poseidon disaster he escaped by jumping over the side. 
Some of the M-2s crew had been more fortunate. One, interviewed by the Daily Mail, was Able Seaman E. A. Evans. On the very day that M-2 went out for her trials his discharge came through, and he did not sail. Because his father had died, he wanted to go home to South Africa and help his mother, so he bought his discharge. It arrived just in time. Another few hours and he would have been, as he said, "with my pals on the bottom". 
A London Star reporter had a strange experience on the day after the disaster. He found himself sitting opposite a sailor in the Tube (Subway). The young man, who is never named in the interview, had "Submarine M-2" in gilt letters on his cap. The Star reporter, doing his job, interviewed the man, who "was labouring under the stress of deep emotion and when I spoke to him he broke down completely". The interview went like this: 
"I began my Christmas leave on Saturday. By an arrangement with one of my mates I stayed on duty over Christmas while he went home to his wife and family. I wish I'd never consented to the change. Here I am, single, with no ties compared to him - and some people call me lucky! Lucky! - To lose my mates and know they've left behind those who will, naturally, miss them more than I should have been missed if I'd been there instead of any one of them! There's just a chance they'll get them up alive." 
Now the weather took a hand, and even that slim chance faded. The divers went down all right, but when they could go down heavy seas, wind and tides made it impossible for them to reach the contact. They had got to 70 feet down, 30 feet short of the bottom. Then with the return of the lifting lighters, which had been at sea off Portland Bill, all hope for the crew was drowned. In the meantime the Admiralty were interested in a report that the master of a Newcastle coasting vessel had seen the M-2 shortly before she disappeared - so interested that they sent an official to talk to the captain of the coaster when he arrived at Gravelines, near Calais. The coaster had put into Portland to bunker, and while there the captain had asked in conversation if it was not unusual for a submarine to dive stern first, as that is what he had seen in West Bay, off Chesil Beach on the West of Portland Bill. 
At 10.30 p.m. on January 27 the Admiralty issued another statement: 
"The following information was received tonight from the Rear-Admiral of Submarines (Rear-Admiral Little) who is conducting search operations to the westward of Portland Bill for Submarine M-2: Two objects have been located by sweep-wires, but, owing to the strong tide, divers have had difficulty in reaching the bottom to investigate. Diving is being continued when possible throughout the night. 
In the early hours of Thursday, January 28 the Daily Mail was able to feed new information to the Admiralty. Their reporter had located the captain who had seen a submarine dive stem-first near Portland Bill before the Admiralty officials could reach him. In a dramatic dispatch from Gravelines, near Calais, the Mail's special correspondent reported: 
"I have just had the first interview with Captain A. E. Howard of the Newcastle-on-Tyne steamer, Tynesider, the last vessel to see the M-2 before she disappeared. I found him asleep in his cabin just after midnight two miles off Gravelines Harbour, which the Tynesider will only be able to enter at 3 am. 'There can be no doubt', Mr Howard said to me, 'that the submarine I saw yesterday morning is the same which disappeared off Portland. I was coming from Charleston, Cornwall, with a cargo of China clay yesterday at 11.30 am. As I was getting near Portland I saw the submarine. I could read quite clearly her mark M. She was on top of the water, but I soon noticed that her head was getting right out of the water. Before I could approach I saw her sink rather suddenly, her stern first. I did not pay too much attention to it at first, since I had never seen a submarine dive. However, when I called at Portland at 2.30 p.m. I told the news to a man on the quayside and asked him if it was the right way for a submarine to go down. He said he had never seen a ship sink, so I did not trouble anymore. When I left the harbour I met a submarine going in and I thought that it was the one I had seen earlier and that everything was all right. Of course I was sorry to learn this evening on the wireless that M-2 was lost. But the position the Admiralty gave is not a good one. When I saw the M-2 she was approximately eight miles NW by N. from Portland Bill, two and a half miles from shore. I am afraid they are searching in the wrong place." 
By 8 am on January 28 the Rear-Admiral Submarines had been in touch with the Admiralty, who issued two statements. The first detailed a signal from the Rear-Admiral: " 
Regret no progress during night. Am concentrating our efforts on the two obstructions previously reported, and also in vicinity position, seven miles 300 degrees from Portland Bill, to which Tynesider and schooner Crown of Denmark have drawn attention." The second Admiralty statement was an elaboration of the first: "The following information was received last night from the captain in charge, Portland: The master of the motor auxiliary schooner, Crown of Denmark, reports that while on passage to Portland he was approximately 16 miles at log S. E. of Lyme Regis, about 6.40 p.m. on Tuesday, when he saw on his port beam a very sudden bright light of about three seconds duration, which dimmed, reappearing very bright, and then disappearing altogether. The light was followed 10 minutes later by two loud explosions like guns going off. Weather was thick at the time. His craft anchored at Portland at 9.30 pm on Tuesday. Neither the light or the explosions can be accounted for." But the fact that both the Tynesider and the Crown of Denmark reported something in the same area had caused the new search there. Captain Hunt, the master of the Crown of Denmark, said later: "Immediately I saw the flash I thought something was wrong. It was a brilliant white flash and was repeated two or three times. There was then a loud report, which echoed over the water, but I could not see anything on the surface to account for it. It occurred to me at the time that it might be a submarine, and as soon as I heard that the M-2 was missing I put into Portland and made a statement to the authorities." The position that Captain Hunt gave was within half a mile of the place where Captain Howard of the Tynesider had seen M-2 dive. 
The Navy now had several positions to search, and those who knew West Bay, which was now being called "Dead Men's -Bay" - had every sympathy with them in their search. For West Bay was also called "The Bay of a Thousand Wrecks". There was no telling whether the sweep wire from the searching vessels had caught an old wreck or the M-2 - until divers went down and checked the wreckage. For example, HMS Sabre, the destroyer, caught something in her sweep wires. She cast her lead, and it came up covered with paint. She dumped an anchor on the spot, and oil welled to the surface. The M-2 releasing oil recognising that she had been located, or an old wreck? 
HMS Thruster, another destroyer, heard tapping on her listening gear. Natural? or the M-2 trying to attract attention? Either way, it was another position for the divers to search and the divers, no matter how hard they tried, could not always reach the obstruction at the end of the sweep wires. The tides swept them back at each new attempt. The whole of the submarine's possible exercise ground was swept again and again, and more and more obstructions were found. At 8.30 p.m. that day the Admiralty put out a new statement. It gave some idea of the difficulties facing them: 
"The following information was received at 6.40 pm from the Rear Admiral Submarines, who is in charge of the search for M-2: We have temporarily abandoned operations on the obstruction first discovered on Tuesday evening as the sweep keeps slipping so that divers cannot reach it. The divers have not reached the other obstruction found yesterday, but may do so at next tide. Further search of the area today has revealed another obstruction, North 30 degrees West, six miles from Portland Bill. Divers have been on the bottom near it and have so far failed to reach the obstruction. The operations continue". 
Everyone in the Royal Navy knew that they had no more time, but they worked on and so did the exhausted divers. Diving went on all night by the light of underwater lamps. At 5 am on January 29 Rear Admiral Submarines again: 
"The obstruction discovered six miles North 30 degrees West from Portland Bill is an old wreck. Shall sweep in the vicinity, as an earlier sweep, which parted, brought up a pair of submarine hand flags in canvas case. General search will continue as well. No hope now of saving life." 
That night from Admiralty: "The latest information received from Rear-Admiral Submarines is to the effect that divers have examined further obstructions, which have proved to be old wrecks. The search still continues". And later: "The Secretary of the Admiralty regrets to announce that in view of a report now received from Rear-Admiral Submarines, who has been attempting to salve the sunken submarine M-2, it is no longer possible to hope for the rescue of any of the officers and men on board". At the same time as this chilling statement the Admiralty issued a list of seven officers and 53 petty officers and ratings on board the submarine at the time, adding "their death must therefore now be presumed". 
The King sent his deep sympathy and that of the Queen to be conveyed to the families of all those who had been lost, and also to all the officers and men serving in His Majesty's submarines on the loss of their comrades. Still there was no sign of the position of M-2. The submarine signalling flags bore no distinctive markings, and could have come from anywhere. Every time the divers went down they found an old wreck - and there were said to be at least 200 in West Bay dating from the Spanish Armada. But the diving went on, for the Navy now considered it imperative to find out what had happened to the M-2 - "in the interests of the submarine service as a whole". 
After five days and nights of continuous searching those who were in a position to question authority were raising the usual questions. Was there any point in keeping submarines in peacetime? Why were the divers unable to reach the contacts? This last one was easily answered. Although the weather was calm, currents made diving very difficult. One diver, for example, went down and was laid flat on his back by the tide. 
A more difficult question to answer was the story of the peculiar behaviour of M-2 on Wednesday of the week before her last dive. When the M-2 was in dock at Portsmouth that day there appeared, according to dockworkers, to be considerable difficulty in handling her. First her stern went up in the air and then her bows, before she disappeared under water on an even keel. Divers went down with her next time for about five minutes before she came to the surface again, when the stern-up, bow-up procedure was repeated. 
On February 1, 1932, the Daily Mail reported a much more serious possibility in the words of Commander H.M. Daniel. Said Commander Daniel: 
"It seems possible, however, that the M-2 was practising a special evolution peculiar to her function as a seaplane carrier. She may have been practicing getting her plane away in the minimum of time from surfacing after an unseen a approach underwater and it may be that over-keen men attempted to gain access to the hangar a second or two before the submarine was right up. The front doors of the hangar would obviously be designed to be watertight; their existence, nevertheless, appears to be in conflict with well-established principles of submarine design. Not only are the huge flat surfaces not streamlined, but also they are of a shape ill suited to withstand the great underwater pressures. If these doors had become leaky two or three hundred tons of water may have accumulated in the hangar unknown to the crew and, on the opening of the hatch, may have poured in an overpowering deluge into the boat." 
No one could dismiss Commander Daniel's theory - especially in view of Captain Howard's stem-first of the M-2 sinking. This theory, thought experts at the time, would explain the lack of signals from the submarine. If the theory was right everyone on board would have been drowned almost at once. 
On February 2 newspapers reported a fisherman saying that he had picked up the body of a man in a white sweater (standard submarine wear) while fishing in West Bay. The body, unfortunately, had not been recovered, and had fallen back into the sea when the fisherman had tried to haul it into his boat. This was the first clue. That same day, the First Lord of the Admiralty, Sir Bolton Eyres Monsell, announced in the House of Commons that the searching had found: a cap belonging to the coxswain of the M-2 floating in a canvas bag and a collar belonging to a chief petty officer. The cap had been found floating, and the collar had been brought to the surface by a sweep wire. The hunters were obviously getting close. And on February 3 the Admiralty released the news that M-2 had been found, announcing shortly after 11 p.m.: "The Rear-Admiral Submarines has reported that he has located Submarine M-2 position 50 deg 31.2 min N., 5.8 miles from Portland Bill". 
The official description of how the wreck was found was that HMS Torrid, a destroyer equipped with powerful listening apparatus (Asdic), found the contact, and minesweepers confirmed the finding HMS Pangborne and HMS Dunnon with sweep wires. The sounds picked up by Torrid were "of a nature which indicated the presence of a newly sunk submarine". Divers were sent down, but were at first unable to reach the bottom because of the strong tides and poor visibility. Four "diving lanterns" were sent down to the divers, and at 10. 11 pm - over eight days since she had dived to disaster- the divers reported that it was indeed the M-2. The divers had gone down from HMS Albury, and they found M-2 in 18 fathoms of water. A wreck buoy was three miles from the point where Captain Howard of the Tynensider had reported seeing the M-2 dive, and not far from the position spotlighted by the report from Captain Hunt of the Crown of Denmark. One immediate question that this raised was: Did the M-2, crippled by an inrush of water, still manage to crawl two miles under water, unable to rise? Or was the sighting wrong? As the hours passed, more details were disclosed of the way the submarine was found. The Portland race, which divers reported as flowing at seven knots at times, hampered the search, and it was not until one diver saw the conning-tower letters"M2" that the discovery was confirmed. The divers found her with her stem in the sand and shingle and her bow slightly raised off the seabed. This gave rise to theories about the possibility of some sort of stem-dive to disaster, but later teams of divers sent down to the wreck were unable to find any damage to the submarine. The bow was however, high enough of the seabed for the divers to walk underneath. The M-2 was lying close to another wreck or wrecks, and these were variously described as "a U-boat and Q-ships". One report, which it seems difficult to pin down to any authority, said that the M-2 was in fact pinned between two wrecks. This provoked more theories about the sub creeping forward disabled over the seabed in a desperate attempt to reach shallower water. But, for the time being, the reason for the disaster remained a mystery. And that mystery had to be solved. Team after team of divers were used to survey the sunken boat. On February, 5 the day that a memorial service was held over the sunken sub the Admiralty, made a late night announcement that started to throw some light on the cause of the disaster: "Diving operations on the M2 up to date have revealed that the hanger door and the upper conning tower hatch are open and that the forward hatch and engine room hatch are closed. It has not yet been ascertained whether the lower conning tower hatch and the hatch inside the hanger giving access to the interior of the submarine are closed or open. It has been decided that the salvage of the M2 is to continue weather permitting." 
From that statement it seemed reasonable to assume that the M2 was practicing a rapid a rapid launch of her seaplane -surface, open hanger doors, catapult airplane, close hanger doors, submerge. Some of those who had worked closely with M2 believed this was the drill being practiced and said that when the conning tower was clear of the surface, the hangar doors were still submerged.

Ron Harvey