How deep can you theoretically go on single tank?

[Azza]

ClevelandDiver, I remember an article back around '94-'96 that involved Mr. Gilliam again where he and a group of other divers, maybe five divers, did a deep air dive to around that depth. The writer of the article, one of the divers, told of trying to slow his descent by grabbing the descent line, actually a cable, and getting fish hooks in his hands. I wish I remember which publication it was.

It was called the Wah Wah. I think it was in Aquacorps. I might have a word copy of it somewhere. Bob Raimo wrote it i think
Very enlightening read. I never realised how many stupid people dived.

<edit> DOH! Should have read the whole thread</edit>

 

[Diver0001]

With a single tank?

unlikely.

 

[ScubaFreak]

I don't think this is exactly what you meant to say and some people may get the wrong impression.
Once you go beyond 1.4PPO2 you are playing with statistics which get worse the longer you stay there.
Sure I know divers that have bounced to 85m without taking an O2 hit. Doesn't mean it's been disproven.

Spot on Mike, my fingers typed what i was saying not what i was thinking

at the end of the day, people have gone beyond the 1.6 partial pressure boundary, and it didnt have any bad effects...

 

[dilligaf368]

all the limits aside, how deep can you go on a single cylinder? was just wondering cause i keep hearing about recreational limits etc. etc. but see divers all the time go well beyond em and still have enough air to do their deco stops. just wondering if you guys really follow the 60ft max limit for OW, and 130ft limit for recreational diving?. i wasnt trying to be reckless, careless or stupid or anything but i may have been a bit naughty in my last couple of dives

Using the USN diving manule it states that if the diver goes to 200' then at a rate of desent of 60' per second the total time of decent would 3.1 minutes and having only 4 minutes before deco time charge is only 5 minutes. The diver would have to decend to 200' in three minutes look around for 2.5 min and leave the bottom before the five minute mark and start acending to the surface. No Decompressing requiring stops to the surface. Thats what the book says. B

 

[MikeFerrara]

We did a deco stop at 70' for 4 minutes.

Why 70 ft?

My buddy consumed less air than I did and I used 1740 PSI.

And if your reg had free flowed at 200 ft?

Yes I do trust dive tables as well as computers, we used both. You don't?

Not really. Which tables do you use for a 200 ft dive? I don't usde a computer and there isn't any table I know of that I would use "as is" for a deep or long dive. Ever notice how drastically user setable parameters can change the suggested profile when using decompression software? Which is the real ascent schedule?

I had done 9 other dives to between 170' and 180'.

Were these bounce dives on a single tank too?

Look, I'm not saying this is for everyone but like so many solo divers out there, some who won't admit it, I am responsible for my own safety and although you obviously think this is reckless you were right when you said people have gone much deeper than 207'. Perhaps you should talk to the agencies who give out dep divers certs.

Why should I talk to the agencies that issue certifications for deep diving? I don't know of an agency that recommends doing 200 ft dives on a single tank. Do you? I don't have a problem with deep diving. I've done a hand full of dives in the 300 ft range. Those were trimix dives on double 104's with an al 80 stage and 3 decompression gasses. I've done a bunch of other dives in the 200+ ft range and those were trimix dives on double 104's with 2 decompression gases. Some of you guys said that you like all the gear. Well those were great dives for some one who likes gear because I was carrying a bunch of it. There are dive shops that don't stock as many regs and tanks as we sometimes pack for a single dive. LOL

As far as doing it on air...I know divers who have done cave surveys at 250 on air. On the other hand I went through my training when it was common to be trained in deep air before moving on to mixed gas so I've done dives approaching 200 ft on air (always wearing doubles and at least one decompression gas). We dived to 170 on air in class even. The point is that I've seen first hand some of the clusters you can run into on air at those depths. After having done it on air and mix I can say that there isn't anything underwater anywhere in the world that I want to see bad enough to go back to 200 ft on air. IMO, 200 ft dives and single tanks don't even belong in the same discussion.

I love deep diving and prefer it in caves cuz open water is just too risky. LOL but IMO a single al 80 is for playing in the shallows not for real diving. I too take responsibility for my own diving but you'll rarely catch me even at 100 ft with just a single tank. Decompression with only air to breath...YUK! I like gear too so when I dive deep I bring some of it with me. I'm also an engineer and like numbers and planning so I go through the numbers and do some planning for deep dives.

For others who want to see deep wrecks, caves or just see what the sand looks like below 200 ft, I say go for it. However, there is some trainning (formal or informal) and equipment I'd recommend getting first.

 

[MikeFerrara]

yup forgot to mention the gear. at 150 feet you have to have complete faith in your equipment, its your only lifeline to the surface. now how about that?

I've seen too much gear fail to ever have complete faith in it. That's why we include some redundancy for deep diving.

 

[MikeFerrara]

I was not "narced out". As I said I had done other deep dives and knew the symptoms.

I wonder...Did you know that one of the symptoms is not recognizing the symptoms? Narcosis is funny that way and it kind of sneaks up on you. It pretty easy to swim around while your pretty narced just like I could be pretty drunk and still get from one end of my house to the other. The test comes when you have to really do something like think your way through a new problem.

By "coming out of the closet" and posting this dive, I knew that there would be some criticism but I know there are a lot more people on this board that have done 200' and more.

But the criticism isn't for going to 200 ft. It's for going to 200 ft dressed for 30 ft.

Pushing the limits? Yes. Stupid, as someone said? Perhaps in their eyes. There is calculated risk in many of the things we do. Just make sure you do the calculations first.

Divers have gone deeper than 1000 ft on open circuit and they have done 300 ft dives with hours of bottom time and many hours of decompression time. You didn't push any limits other than those that were self imposed by deep diving with shallow diving equipment.

 

[miketsp]

Why would you want to go to 200 feet on air? You'd be so narced out of your mind
..snip..

Well I remember once when we had to recover an object weighing about 5 tons in 85m and the only available tanks on board contained air. We knew exactly where the object was because we had located it by underrunning a communications cable that ran into it but this cable could not sustain 5 tons. There was supposed to have been a heavy cable with a bouy, but for some reason it was missing. So the diver (professional) reluctantly had to make a bounce to that depth with one objective - to tie on a 5inch polypropylene rope so we could lift it onto the ship.
He told me later that he had a really hard job remembering why he was there even though he was holding the free end of the rope in his hand, and as for remembering how to tie a knot he only managed it on the 3rd try.

 

[Diver Dennis]

Mike, I know that this was pushing the limits but dressed for 30'? C'mon... As I said, I know there are more people on this board that have done the same dive and deeper. That dosen't make it right for anyone but I did this for me and no matter how long we argue, we won't agree on anything to do with this dive.

 

[Soggy]

An aluminum 80 has no place deeper than 100' and is in it's prime around 30'. Some very very simple math will show you why...below 100' and you basically have *no* contingency. If you don't know how to do that math, you shouldn't be diving deeper than 30' anyhow.

Diving to 200' on air with a single aluminum 80 with no bailout is just plain stupid. You can rationalize all you want, but it won't change that simple fact. I hope you don't join the Darwin Award club, but with your attitude, I am doubtful.

Mike, I know that this was pushing the limits but dressed for 30'? C'mon... As I said, I know there are more people on this board that have done the same dive and deeper. That dosen't make it right for anyone but I did this for me and no matter how long we argue, we won't agree on anything to do with this dive.