My first out of air incident!

[AXL72]

Bloody hell!

I am glad someone did not have to burst to the surface from 90 or 100 ft. Sheez.

What is the difference between the starting story of this thread and playing Russian Roulette?

 

[John C. Ratliff]

Breathing gas under pressure at 40 feet and making an emergency ascent is a risk.
At 40 feet you are loading nitrogen into the tissue albeit a very small amount.

Free diving and holding your breath for a few seconds vs. breathing gas under pressure for 15 minutes, I am missing your point.

Yes, you are missing something here. Take a look at the decompression tables, and you'll find that at 40 feet there is a 200 minute no-decompression limit. You can simply ascend to the surface without problems. He had what, 15 minutes bottom time? That doesn't sound like a problem to me with nitrogen in tissues. This should have been covered in the scuba course.

www.ndc.noaa.gov/pdfs/NoDecoAirTable.pdf

Now, given that, I wonder whether there was a pressure guage on the surface that he could have used to determine what his tank pressure was before entering the water. It was probably under 1000 psi.

I would probably have insisted on a pressure reading before getting into the water, and once in, would have told them that I would take off the unit, hand it to them, and stay with them free diving. 40 feet is not a big deal in an out-of-air situation. A J-valve would have been nice though.

SeaRat

 

[Cacia]

I mean, SeaRat, thank-you for that! I do understand the viewpoint that he set a very bad "example". (who was watching though?), I just never understood the viewpoint that what he did was life threatening. I see things every week that I consider far worse. A common one is people blindly following a string of other tourist divers into caves, operators putting out- of -shape people in on "Ninja dives" and rough surface conditions. Experienced "PADI rule-followers" drifting without surface markers!
I loved his post because people who travel need to be aware of what goes on in other countries. They need to be able to "process" and not just "follow the leader". I thought the "out of air post" illustrated that point very clearly. He never had enough bottom time at that depth with a partial fill to kill himself, unless he did not know how to swim. The yahoos that he was diving with probably new that.

 

[timle]

While I don't think he would have gotten into Nitrogen trouble its worth noting no decompression limits are based on an assumed max ascent rate. An emergency ascent is probably going to blow that limit out of the water.

I think the larger danger though is an air embolism or a lung expansion injury. These are not common with free diving as you aren't inhaling pressurized air.

 

[John C. Ratliff]

While I don't think he would have gotten into Nitrogen trouble its worth noting no decompression limits are based on an assumed max ascent rate. An emergency ascent is probably going to blow that limit out of the water.

I think the larger danger though is an air embolism or a lung expansion injury. These are not common with free diving as you aren't inhaling pressurized air.

You are correct in the latter case, in that the main danger was from a lung overpressure injury. But there is a reason the basic scuba courses had everyone complete a 20 or 25 yard underwater swim--they wanted to make sure that they could get to the surface in a free swimming ascent if needed. In the US Navy Underwater Swimmers School, we were taken to 30 feet for buoyant ascent training. We were in an open chamber for up to 15 minutes (there were a number of us), and we had to duck under the cover, have an instructor inflate our vest while we held onto the chamber, then let go and do a buoyant ascent ("blow & go"; this was 1967).

If your airways are open and you are exhaling, a free swimming ascent is possible from quite deep water (Cousteau's team member, Frederick Dumas, in the 1950s taught free swimming ascents from over 100 feet).

Frankly, in this case, I think the Pakistani divers had set this diver up, and he fell for it. I would have enjoyed blowing their minds by either giving them the empty tank, then buddy breathing from them for the rest of the dive, or doing a free swimming ascent and re-joining them repeatedly from the surface (I carry a snorkel on all dives). As it was, I think this guy not only was set up, but he did not realize it and simply "acted like an American."

And yes, there was one post that questioned whether there was some subtile racism in this thread--there was in my opinion at least ethnocentrism. I think these were better divers than the thread's originator imagines.

SeaRat

 

[AXL72]

I think we all are smart enough to know that from 40 ft, he probably had no threat of hitting a decompression limit. But, shake up a bottle of pop for a few seconds and open it fast and compare the results to shaking up a similar bottle of pop for a few seconds and opeing it very slowly.

Also, for future reference for others, their are other situations that may compound the situation, such as repetitive dives and built up residual nitrogen, exceeding a previous dive's decomression limit, and not to mention, deeper dive depths than 40 ft.

There was an interesting post on here about a diver who stated that he got bent after completing a 30 ft max depth dive. I am sorry I do not have the link readily available.

Frankly, I think it is safer to get into the habit of correct ascent rates and diving prepared to successfully do the correct ascent rate. Even though a safety stop was probably not required, it is just safer to be in the habit of doing so, regardless of depth, especially on repetitive dives. Therefore I recommend that the correct ascent rate and a safety stop be executed every time, regardless of depth, so that it becomes reflexive. Is this conservative? Yes, absolutely. Any harm in doing so? No, especailly when considering how little air is actually required at 15 to 20 ft for 3 minutes.

I agree, the diver may have been set-up. The goal of this experience should be aimed at not repeating this type of "trap", again.

Finally, I disagree that the diver acted like an American. Many Americans would have either busted the jaws of the SOB's, afterwards, or would have thought, "Safety first", before avoiding the dive altogether.

 

[John C. Ratliff]

I think we all are smart enough to know that from 40 ft, he probably had no threat of hitting a decompression limit. But, shake up a bottle of pop for a few seconds and open it fast and compare the results to shaking up a similar bottle of pop for a few seconds and opeing it very slowly.

Also, for future reference for others, their are other situations that may compound the situation, such as repetitive dives and built up residual nitrogen, exceeding a previous dive's decomression limit, and not to mention, deeper dive depths than 40 ft.

There was an interesting post on here about a diver who stated that he got bent after completing a 30 ft max depth dive. I am sorry I do not have the link readily available.

Frankly, I think it is safer to get into the habit of correct ascent rates and diving prepared to successfully do the correct ascent rate. Even though a safety stop was probably not required, it is just safer to be in the habit of doing so, regardless of depth, especially on repetitive dives. Therefore I recommend that the correct ascent rate and a safety stop be executed every time, regardless of depth, so that it becomes reflexive. Is this conservative? Yes, absolutely. Any harm in doing so? No, especailly when considering how little air is actually required at 15 to 20 ft for 3 minutes.

I agree, the diver may have been set-up. The goal of this experience should be aimed at not repeating this type of "trap", again.

Finally, I disagree that the diver acted like an American. Many Americans would have either busted the jaws of the SOB's, afterwards, or would have thought, "Safety first", before avoiding the dive altogether.

A couple of points.

Your analogy of a pop bottle being shaken up and the cap lifted slowly is not a correct analogy for the situation. Try the following analogy, shake up a non-carbinated beverage and see whether it makes any difference whether the cap is removed slowly or fast. But you are correct about the ascent rates, and habit of taking a safety stop.

Concerning the diver being bent in 30 feet of water, there must have been some extenuating circumstances. Either his depth was not correct, he stayed at that depth for an extremely long time (2 hours or more), or he perhaps went flying after the dive.

If you'll look at my comment that the diver "acted like an American," notice that this is in quotes. I agree that many Americans would have been upset at these circumstances. But as you will recall, these were Pakistani Special Forces, and rather than acting normally, it would have been more appropriate to act like a Special Forces team member. As a former member of a Special Forces unit (USAF Pararescue), I know a bit more about the mental conditioning than perhaps other divers on this board. He was being tested. They wanted to know whether they could trust him in a "situation" during a dive.

There is a perception about Americans by other peoples that we are belligerant, arrogant, and pushy. The Special Forces personnel were pushing his buttons to see how he would react, and he reacted as they expected an "American" would react.

My thought is that I would act differently, as if this was normal, and simply swim around borrowing the other diver's air when needed. I would have stayed with them without an air supply until the dive was completed, or if they refused, simply surfaced and continued breath-holding. But I would have handed them my scuba so that they had to lug it around, and simply enjoyed myself.

If they had seen a diver doing this, it probably would have gained their respect. The way it actually went down (as reported here in the original post), he did not dive again with these guys.

By the way, this is not unprecedented. Have you ever been to Crystal Springs when they had their shows going? If so, you would have seen "mermaids" using air hoses after extended breath-holding during the show (which if my memory is correct was about half an hour long, or more), at depths up to 40 feet deep.

You will note that I'm stepping out of my role as a safety professional, and back into the past when I was a member of the Special Forces. With this scenario, there was no safety hazard, so my goal would have been to do some mental gymnastics with this group of Special Forces divers, see how they would react to the unexpected, and I'll state it again, try to "blow their minds" with a diver who wasn't freaked out by what they had done. Who knows, it may have resulted in some real experience-sharing after the dive if this diver had done something like this, rather than presenting a scene.

SeaRat

 

[Cacia]

I am old enough to remember those mermaids! My dad would take us all there right before Ross Allen's Reptile Institute, where we watched Tarzan wrestle the alligators. Then we would hop over and watch them milk the rattlesnakes, then we would go for a dive and he would drag us kids in the caves, pretty much against our will. (Not that I condone that, he thought he "making us tough")

I really enjoy reading posts by divers like the one above. I think his credentials and broad experience base add a lot to diving discussions. It would be a real shame if the "PADI fundamentalists" could not gain from the broader perspective of diving's history. I have nothing against PADI but many people recite the "standards" like they are reciting the scriptures to everyone else. As far as I can see, this Pakistan diver was well out of PADI "juristiction" and under no real moral obligation to anyone.

Should he be able to tell his story on Scubaboard? I guess thats the question. I, for one, think so, because look at the useful discussion about Nitrogen loading that has ensued.

 

[discrepancy]

Where is the intolerable risk in this adventure? While it is not the kind of thing I'd make a habit of, I don't see this as being any more threatening that something like driving in bad weather. We are talking a depth that many divers could handle in a free dive.

Well, I for one would have dived with those guys on the day. Sure it is a transgression of all that is writ in the PADI scriptures. But you can look at the situation and assess the risks.

With a half-full tank you can bet on 30, maybe 40 minutes of dive time if you stay above 30-40 feet.

No depth gauge? We don't know what the weather and viz was like, but from 30 feet you should be able to make out where the surface is. Did the guys on the boat say what depth the bottom was? That would be another cue. In any event, given the conditions an experienced diver should be able to tell whether he's at 15 feet with sunlight and waves above, or heading towards 120 feet with no colour, dark, squeeze and many equalisations, not to mention the time and effort you'd need to swim down beyond 100 feet. If it were me with no SPG, I would keep the surface in sight.

So, tooling around in shallow water for a while without gauges should not be a big issue. What's the worst that could happen? Out of air. OK, you know it's on the cards after a certain time, so keep it shallow and if it happens, just breathe out and swim up. I wouldn't be bothered swimming sideways to look for my 'buddy'. The other divers were obviously expecting you to just surface, and the joke about adrenalin was just that.

Also, remember there is no rule that says you have to dive till you're ooa - 20 minutes at 30' on a half-full tank would have been fine.

I notice that no-one died on this dive, including SeaHound. Maybe the diving culture there was different, but don't forget PADI is catering to the lowest common denominator. Sure, sticking to the PADI rules is a safe way for most recreational divers to enjoy an exhilarating sport. But there are other ways to dive, and let's not get all high and mighty when other people decide to dive differently.

 

[amport]

I also would have done this dive....
What the heck 40 feet, no one lives forever any way.
Life is a grand adventure or nothing at all.