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View Full Version : Video-spot the deep dive mistakes



The Publisher
05-22-2008, 03:55 PM
http://www.youtube.com/watch?v=Gt0XaWiqLyU

bottlefish
05-22-2008, 04:13 PM
Beyond managing to get back to the surface again, I can't see anything that they did right!

What on earth are they trying to prove, IMHO a couple of idiots waiting for the hammer to find the full chamber!!

seasnake
05-23-2008, 04:46 PM
At least buddy had his snorkel with him! Awesome ... wow ... and the best part is they were so proud of themselves! High fiving and okay'ing all the way to the surface! It would have been darwinian justice if that spinning prop on the boat would've minced them up as they tried to climb back on ...

shinek
05-23-2008, 05:42 PM
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.

amtrosie
05-25-2008, 05:56 AM
OH MY GOD!!!!! :eek: :eek:


How are they even alive?


- first, single tank dive?
- second, stage bottle is not secured at all!! can be very difficult to access quickly, also when using reg, can be pulled out of mouth very easily.
- third, computer shows 293 feet for 5 min. The deco for that is at least 1 hour with multiple stops. You need more gas than what they were carrying.
- fourth, none of the tanks are marked.
- fifth, their gear is hanging all over the place. Nothing will be accessed easily. the pressure gauge of the one guy was just waiting to be caught! At that depth, that is instant death!!!!
-sixth, note the fins on the one diver. they are free diving fins. they are more flexible, making one work harder to swim. more work= more gas consumption.
-seventh, notice the number of times the cameraman checks his computer, that is nitrogen narcosis. Not remembering what you just looked at is a classic sign. A clear head is imperative at those depths.
-eighth, A controlled descent as well as a controlled assent are required to off-gas properly. That requires more gas. On that note: There is obviously no dive planning, for there is not enough gas for an emergency that may occur.

That is for starters

bottlefish
05-27-2008, 09:52 AM
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.

shinek
05-28-2008, 05:29 PM
Thanks for the comments and no offence taken ;), it all make sense to me, but think I'll stick with my recreational diving for now. Plenty to see and do between the surface and 130-ish.

Interesting thoughts re: redundancy, the obvious things like sufficient air (gas), backup computer, plan on a slate etc. however, things like a spare mask would probably not have been on my list but as soon as you mention it, it makes complete sense. Presumably, all stuff one would learn to think about during the appropriate tech training.

BigBlueTech
03-01-2009, 09:07 AM
There is no way, any of these guys ever received formal professional technical diver training.

monkey see... monkey do

rubber chicken
03-01-2009, 02:50 PM
Besides the total lack of redundancy etc already mentioned, having your SMB clipped to your gear !?!:eek:
I'd never have anything tied to me that connects to the surface. My reel is hand held throughout, any problems and it is simply a matter of letting go. I've heard of enough instances of divers being hauled to the surface by passing boat traffic to want to avoid that possible scenario.