Posted by RaiderKarl on March 19, 2001 at 09:57:08:
In Reply to: Re: Mike Kane was right about my dive computer posted by Sea Scuba on March 18, 2001 at 11:11:26:
I am not going to mention my maximum depth, because I dont want this to become a numbers game based on egos here on this web site. All I will say is that I reached my own personal maximum depth on this dive Saturday that I described. Other more experienced divers' deepest depth is surely deeper than mine, and some might not be as deep.
If I would have stayed at my own max depth any longer, I clearly would have blacked out. It was not at all due to narking. The narking for me always starts mildly at about 110' then progresses from there. I had a mental algorithm that I repeated to myself to monitor the effect of the narking, which consisted of the following: monitor depth, monitor turn-around air pressure, monitor time elapsed, adjust buoyancy, look around, evaluate and proceed, or else turn around.
As the narking proceeded, I noticed that I eventually sluffed off everything in the algorithm except "monitor depth, monitor turn-around air pressure, continue or abort." When I decided to turn around, it was a quick decision based on the sudden appearance of the basketball-sized white tunnel, which I had not expected at the depth I was at.
The narking was already familiar to me based on my other previous deep dives. Narking didnt catch me by surprise. The white tunnel, which began to close down in size, is what surprised me, at which point I immediately turned around and headed for my first decomp/safety stop at roughly one-half of my deepest depth.
At some point between my deepest depth, and my first decomp stop, the white tunnel went away, and I was really glad too!
Although my planning of my air consumption at max depth did give me plenty of air left over, such that I never reached my air turn around point (one half of air pressure plus a reserve), I exited the water with 700 psi remaining in my 120 cu ft steel tank.
Normally I would have breathed down my tank pressure to much lower while at my last decomp stop of 10 feet, but I was diving at a rough beach, and the exit might have required more air than just a couple of hundred PSI in my 120 cu ft tank. So I surfaced from 10' and exited when my computer told me it was OK to do so, even with lots of air left. By then, the Navy/NOAA decomp had been finished already by several minutes.
The problem with my particular dive computer, the Suunto Vyper, is that if you disobey the decomp instructions, then it puts itself into a lock down violation mode, and you cant use it again all day. The good thing about that is that it motivates me to follow their decomp algorithm, which so far has always been more conservative than the Navy/NOAA tables. The bad thing is that I hate being told by a machine what to do.
My friends on this dive finished their dive about the same time that my decomp stops ended, so as I was surface swimming along the edge of the kelp bed slowly, I saw them swimming below me on their own egress paths.
I am not a scuba instructor, and I dont ever want to be. I also do not want to appear to advocate deep diving on air by my words or by my example. I speak/type here on this scuba web site because all or most of you are extremely bright and experienced divers, and I appreciate your thoughts and input.
The D.I.R. group including MIke K., whom some of you like to snipe for whatever reason on occasion, are as valuable as anyone else is to me, because everyone has a personal opinion based on their own unique experiences. I am not a crusader for any causes or organizations, so I can ignor the banter pro or con for D.I.R. either way. But I do benefit from the discussion and the technical topics here.
I have also appreciated each of your comments here, those of you who have commented. I am a better diver today than I was three days ago. I know better my own limitations, now. Thats why I push my limits when I myself dive. When I dive with other people, or with dive students, I dive very, very, very conservately. And I definitely dont suggest to them or speak of my own personal stunts. I was specifically told that I would be bounced out of the divemaster program if I ever did that. NO putting your tank on over your head. NO talking about deep diving. Etc. Thats what I was told.
Sea Scuba gave the most telling observations of my post, so thank you, Sea Scuba! You are quite right!!!
/s/ RaiderKarl
NAUI OW1 '75, SSI AOW & Rescue '00, etc.
[TDI is next]