Deep Diving on Air

[dumpsterDiver]

Well, since the guy who died was a friend of mine ... and I still dive with one of the guys who survived that night ... I'll give you the crib notes version of what happened.

Instructor dude wants to do a 200-foot bounce dive. Convinces his DM-candidate (my friend) to come along. Then he gets a really NEAT idea ... why not combine this with his ongoing AOW class. He'll have them do their deep dive and night dive all in one ... a quick bounce to 200 feet off a clay wall in Commencement Bay. There are three AOW students, two with less than 15 dives total, and another friend.

Instructor dude buddies up with one student. DM candidate with the friend. And the final two AOW students are buddies. It's dark, windy, and recent rains had put enough runoff into the water to put visibility between 3 and 5 feet down to about 30 fsw, where you could get below the halocline.

The three buddy teams swim out to the wall ... about a 15-minute surface swim ... in chop and darkness. Keep in mind that two of these were very new divers. They start the dive. Before they clear the halocline, the two AOW students who were buddied together get separated and bail ... they never made it below 30 feet. They surface swim back to shore. The other two teams descend down past the wall, hitting bottom at about 205 and immediately begin their ascent. Four went down, three are coming up. DM candidate looks down, sees a light, and goes back down. Sitting on the bottom is AOW # 3 ... too stupid to move. DM candidate grabs him and starts hauling him back up. Probably due to exertion, DM candidate runs out of air at about 160. His final act was to reach out and inflate AOW #3's BCD, rocketing him to the surface from 160 feet. Dm candidate then drifted off into oblivion. That was the last anyone saw of him until 10 months later, when another friend of mine found him half-buried in the mud at just over 200 feet. AOW #3 spent the rest of the night in the chamber at St. Joseph's. Instructor dude was permanently banned from NAUI.

Believe it or not, that's the short version ... as a footnote, the guy who found the body had a narcosis-induced accident of his own a few months ago and is still on the mend. I truly hope he's able to fully recover and dive again.

... Bob (Grateful Diver)

Very sorry about your friend. Clearly that was not an appropriate dive for the people involved. It sounds like my assumption was correct and that the root cause of the fatality was narcosis.

Here is an old thread I started where deep air (probably narcosis) caused me to make some errors that nearly killed me.. I am not a proponent of "deep air" for anyone, but the true dangers should be discussed.

http://www.scubaboard.com/forums/accidents-incidents/134163-scooter-salvage.html

 

[lamont]

I did a number of dives last year with people who did deep air dives because they did not want to pay for helium. It appeared to be fairly common in the area of South Florida in which I was diving.

On the other hand, not a single one of them was doing the single tank bounce dives being described here. Every one of them was using well accepted technical diving protocols. They all had plenty of gas with them. They had redundancy. They had made careful dive plans with decompression profiles plotted out. They all used high nitrox percentages for accelerated decompression.

Not wanting to pay for nitrox on a planned 150 foot dive is not a reason to throw all other safety factors away, too.

Yeah, but the guy that NWGD is talking about who recently had DCS was diving deep air technically and he was very experienced with it, but that still didn't stop him from having a deep water blackout (probably due to CO2) and nearly dying.

And that's the trouble. You can do a bunch of dives and build up tolerance and experience and confidence diving deep on air, and then one day it goes a little bit sideways and CO2 buildup causes you to slide down into the incident pit and the nitrogen impairment and thick gas at depth means that you cant get out of it.

 

[Simon-]

Hey look, this thread is a circle. Let's keep going round and round


Opinions are like arseholes, everybody has one

 

[knowone]

Simple

 

[MXGratefulDiver]

Opinions are like arseholes, everybody has one

True dat ... but the incidents I mentioned earlier, and their causes, were not opinion. They actually happened, and it affected a lot more people than just the casualties ...

... Bob (Grateful Diver)

 

[boulderjohn]

Opinions are like arseholes, everybody has one

But that does not mean all opinions have equal validity. Last week marked the second time this year the heartfelt opinions of a certain church that the world was going to end on that date turned out to be wrong.

Everyone is entitled to an opinion, but if it cannot be supported in a meaningful way, that opinion is worthless.

 

[Peter Guy]

Simon -- your statement "Opinions are like arseholes, everybody has one " while cute (not to mention old) shows either a lack of understanding of various issues OR an indifference to a very important point -- not all opinions are valid (and for not matter, not all arseholes are "valid" either, but I'll leave that to the surgeons).

The issue here is the basis for the opinions -- and that is why the controversy on the basic topic. Some people, perhaps like VDGM, don't appear to have any valid basis for many of his opinions -- they just are what he believes -- call it, if you will, "faith based diving." YMMV

 

[Tigerman]

Very sorry about your friend. Clearly that was not an appropriate dive for the people involved. It sounds like my assumption was correct and that the root cause of the fatality was narcosis.
...

I beg to differ. If they had planned the dive properly they would have had enough air to solve the incident and get everyone back up to the surface alive.
The root cause was ****ty dive planning and unfortunately the DM paid the ultimate price for it

 

[boulderjohn]

I beg to differ. If they had planned the dive properly they would have had enough air to solve the incident and get everyone back up to the surface alive.
The root cause was ****ty dive planning and unfortunately the DM paid the ultimate price for it

Absolutely.

That is the same thing that happened in Cozumel. They overcame the problem that was caused by narcosis (diver went too deep), but because they had cut their air supply margins to the minimum, they did not have enough air to do the ascent properly. Two of them went OOA at 200 feet, and they did a 3-person buddy breathe to the surface with no deco stops.

One of the key points of safe deep diving is to take enough gas with you to give you the time to recover from an unplanned event and make a safe ascent.

 

[MXGratefulDiver]

I beg to differ. If they had planned the dive properly they would have had enough air to solve the incident and get everyone back up to the surface alive.
The root cause was ****ty dive planning and unfortunately the DM paid the ultimate price for it

The root cause was poor attitude ... taking the dive too lightly. Not one of them, including the instructor, was qualified to do that dive. Three of them were obscenely unqualified and were basing their decision to do this dive totally on trust. No amount of planning would've changed that fact. In remarkable ways it mirrors what I read from some posters in almost all of these deep air, bounce dive threads. And it is that attitude ... not the depth or gas choice ... that I find so objectionable.

Bringing more air may have gotten them safely to the surface that time ... but "success" at that level only breeds more complacency. Sooner or later, Darwin makes a margin call ...

... Bob (Grateful Diver)