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Data up to date so far, keep them coming in. I am currently working on follow up surveys for those who have said they have had Hypercapnia, Hypoxia and Hyperoxia Events and will be analysing loop floods next
Results are below. Raw Excel format data can be supplied to those who want it (suitably depersonalised)
| View Results Summary | View Raw Data |
| Hypercapnia Events Summary | Please contact me if you would like |
| Hypoxia Events Summary | to add your experiences into |
| Hyperoxia Events Summary | these summaries |
Even reading these few, some trends stand out immediately (and frightingly). These are MY interpretations. You can draw your own from the raw data above
Quite a few are diving solo (approx 56%), and most worrying, that these are the people who have had the hypercapnia and hypoxia events and have ignored warnings during a dive and gone in the water with gases turned off and checks not done. I have added a risk scoring to each user, based on points. 1 point was added for each safety breach or scrubber overrating etc.
Its also amazing how many people claim to have always done their pre-dive checks but have entered the water with the diluent turned off or some other fault. I suggest some of you need to do your pre-dive checks more thoroughly and stop skipping them
We, typically are Male and in our late 30's/40's, do roughly 70 dives a year, at depths of up to 70m (average 40m) for normally 1 hour, but sometimes longer
Those that have had scrubber breakthrough's are generally (and there have been exceptions) also those that rate it at longer than 3 hours. How many Hypercapnia events does it take to demonstrate its a 180 minute scrubber. We need to do more work on this as the questions are geared toward discovering the minimum durations and we need to examine lots of other factors. Its interesting that the mean time for Scrubber breakthrough and the mean time for peoples personal scrubber rating have both stabilised at around 245 mins. There is probably some significance here. But remember there have been plenty of scrubber breakthroughs below the 3 hour APD limit
Its also possible to start to see that some Instructors teach the Alpinist route and some don't (and what cell and scrubber durations they teach). For the Alpinists out there note that 21% of all users have had a loop flood (not counting those who have done it intentionally), Hose punctures, leaky T piece O rings, bad pre-dive checks and manual injector failures seem to be the reason. But several have had mouthpieces fall off/kicked out or dropped and one had his cut by his buddy!!!!!!! (I'm trying to get more details on that one, mainly so I can avoid diving with the buddy)
Auto Air removal and diluent bail out DV addition is the most common modification followed up by a larger wing and O2 DV. APD should consider dropping the smaller wing as it seems everybody who uses stages finds it not big enough. That's not including all those fitting 4th cells and ADVs
APD stock control also seems funny. The mix of components making up the units is not constant with age. I know when APD should have swapped form old style cells/pillar valves/first stages/tanks/handsets backlit etc etc , but I am seeing a real mix of ages that these items appear on from new. I need to do some work on this a check with a few of you on your answers as this could be an artefact of the survey questions
Beware this is a biased sample and probably of the more active owners and that I personally think Alpinism and solo CC diving to be ways of nominating yourself for the Darwin awards. I have published and will make available the raw data so you can draw your own conclusions
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