An accident waiting for a place to happen

[MikeFerrara]

The point of my post was to point out that 200 foot air dives are not that uncommon in some areas of sport diving. As done in spearfishing it is drop down as fast as possible looking for the big one. If he's not there it's right back up, total time less than five minutes with 1500 psi left. If he is you shoot him and drag him up into shallow water. The total time maybe a little longer but not the time at 200 feet. Most of these divers have been doing this for many years. I know one who has over 30 years of this type of diving. To imply that if you do 200 foot air dives that eventually it will kill you is not fact. I know a lot of divers on this board frown apon spearfishing and many from interior areas of the country don't have a clue about it. IMO diving half a mile back in a cave only to see rock is a stunt.

Captain

Bounce dives for the purpose of spear fishing seem like a special case. Personally I still wouldn't do it at 200 ft with only one little tank but for most divers not fishing a bounce dive like that isn't hardly worth the trip. When I do to 200 ft, I'm going to see something and I'm going to hang out for a half hour or so.

We from the deep dark interior get to do a little spear fishing and we don't all frown on it. LOL Still I'm comfortable stating that I don't think there is anything I could learn about spear fishing that would get me to 200 ft with just an Al 80 and no redundancy. In fact if I was doing it "solo" like many spear fisherman do I wouldn't do it at any depth without some redundancy.

Going half a mile into a cave just to see a rock isn't a stunt but it is silly. We go for a lot more reson than that. I do it because some of the caves I dive are among the most beautiful places on the planet among other reasons.

 

[H2Andy]

IMO diving half a mile back in a cave only to see rock is a stunt.

we don't agree, but it's a whole lot safer, if done according
to procedure, than (1) solo (2) bounce diving (3) to 200 feet (4) on air (5) with a single AL80.

 

[gfisher4792]

Wait a sec... he's an experienced instructor but knows nothing about oxygen toxicity? Maybe my training was different (not much experience with different instructors, let alone agencies), but in my OW class, it was talked about, however briefly.

Never mind his deep diving on air, I find his lack of knowledge scary.

 

[perpet1]

Naw, he's not telling you that...
(213+33)/33=7.45 X .21 = 1.56 PO2
Very short exposure; no worries.
At least not from the oxygen.
Rick

Thanks Rick that initial post had me reaching for the calculator. 1.6 is actually 218 feet if I remember right.

In any case people have and do dive this deep on air and on single tanks. I have done it in the past (bail out and stage bottles) but I probably will not do it in the future as it is rather pointless and in my opinion rather stupid.

I would NOT recommend it to anyone but if somone chooses to do it they should at least know the risks involved. Then if they do it and get hurt it is all on them.

 

[perpet1]

Put it like this - if I posted in a couple of weeks that this person HAD died doing such a dive, I don't believe too many people would be surprised. For me it would be more than a shame - I know his wife and kids.
Thank you Rick & Pipedope for educating me a little better on the oxygen toxicity thing - you are right and I was worried about that - less now. However I don't really see any 'marginal redundancy' here - presumably his buddies tank is emptying as fast as his is at that depth - they are not going to make it down there with full tanks that's for sure - lose one tank and that's surely going to be a BIG problem - or not?

I think you may be a little mistaken here.

If these guys are instructors I would bet their SAC rate is pretty low. A bounce dive to 200' (as long as they did not hang out down there) should provide them "marginal" redundancy for air. I am not saying that it is perfect or am I endorsing it BUT there would be enough air (probably) for both to come up sharing from 200'. Now factor in a problem and all that goes out the window hence "marginal" redundancy.

 

[perpet1]

Wait a sec... he's an experienced instructor but knows nothing about oxygen toxicity? Maybe my training was different (not much experience with different instructors, let alone agencies), but in my OW class, it was talked about, however briefly.

Never mind his deep diving on air, I find his lack of knowledge scary.

I agree this is the issue that should bother most.

 

[mania]

yes, no doubt that it can be done, and it has been done. just like once upon a time,
fires were put out by volunteers using horse-pulled wagons.

but is it necessary to fight fires with horse-pulled wagons when we have
modern fire engines?

wouldn't it be a shame if this person died because they did not take advantage
of the knowledge and techonologies available today?

Andy, there is no question that doing such thing now is stupid. I only wanted to remind that some have done it this way some time ago. And it doesn't mean that they are doing it now - at least my friend doesn't.
Mania

 

[Mortlock]

Wait a sec... he's an experienced instructor but knows nothing about oxygen toxicity? Maybe my training was different (not much experience with different instructors, let alone agencies), but in my OW class, it was talked about, however briefly.

Never mind his deep diving on air, I find his lack of knowledge scary.

Exactly. I don't find the depth on single tank of air too scary, it's more the fact that he knows nothing of oxygen toxicity! :11: I'm only a novice diver but I do know something about it. You'd expect an instructor of any agency to at least have a basic knowledge of OT.

 

[hvulin]

I think human body gets used to air on depth... At least mine does... I can normally do a dive at 57m and have no problem at all (single 15l bottle) but I never do it at the beggining of the season, but after some 20 dives in a row (each of them is over 30m) I feel safe enough... (although I don't do it if there is no reason to do it... - the wreck can be seen from 45m just as well)

but the instructor of ANY category MUST know about OT and he has no excuse for this (and his instructor too)

there is nothing down there that deserves going that deep!

 

[Sideband]

Going half a mile into a cave just to see a rock isn't a stunt but it is silly. We go for a lot more reson than that. I do it because some of the caves I dive are among the most beautiful places on the planet among other reasons.

Do you have any pics of those caves? Would you share them with me? I'd like to see them and, unfortunatly, I have mild claustrophobia so going myself is not likely.

Joe