Video-spot the deep dive mistakes

[bottlefish]

Not being tech trained, I have never been that deep and can't claim to know the ins and outs of it. However, do we know what training these guys had? The film has been edited and so we don't know the total time spent on this dive or much about any decompression they may have done, what gas they were breathing etc. They appear to have nitrox as their second tank, presumably for deco purposes? I tried to read the details on the computer, but couldn't clearly see much other than the total depth which he was obviously showing off.

I'm curious to know what the obvious deep diving errors were from the film. Don't need a 5 page dissertation, but a few bullet points might be interesting.

They had absolutely no redundancy:

Single cylinder on their back, not enough gas to cope with emergencies, if there was a major failure in their gas supply (e.g reg free flow from the depth), they would have been toast
Single dive computer. If that failed, they would have had no idea of their deco schedule
Diving wet suit with a single bladdered BCD. If their bouyancy had failed, they would have had to swim to the surface.... quite a feat, especially in free diving fins.
Only one mask, would have had to calculate and hold depths blind if for some reason their mask was lost.

Perhaps all of these things seem unlikely, however they can still happen. If you're on a recreational dive, all you have to worry about is getting to the surface. On a deco dive, you have to complete your deco obligations, the surface is not an option, so whilst a minimal chance of occuring, the consequences could be catastrophic.

They were flying the dive off their computer, no plan. You'd expect to see arm slate,with depths and times. Flying it live off a computer may provide you with a deco schedule, however you may find you then thrown yourself into O2 toxity problems or gas management problems, the computer won't (generally) calculate for that, you also have to think what to do during the dive instead of having all the hard bit done before hand.

Out of interest, I ran the dive through vplanner, using air at 293' for five minutes. The CNS O2 total was up at 347.7% from accumulated O2 (without allowing for their higher O2 content deco stage). We try to work to a max of 100% when planning our deep dives, anything over this and you are at risk of getting a CNS hit from O2 build up.

They were on air. Safe depth limit for air is universally agreed as 56 metres (approx 175'), they were way over this, risking extreme narcosis and more importantly O2 toxity issues (recomended limit is 1.4 PO2 at working depth, they were over 2.0 PO2).


Bottom line, there is absolutely nothing technical about this dive, they seem to know as much about tech as you do (no offence meant to yourself there ). They are a couple of mavericks who have decided to push the limits of their recreational gear and training to see how much they could get away with... bit of a one way street when they find out.