Bent in Belize--Blue Hole Incident

[ianr33]

That's the point: I dive the same with the comp or w/o it cause I do not rely on it.

Let me make sure I understand this.

Lets suppose you do a 100 foot dive on air for 15 minutes. Then you ascend to 50 feet. (This is a very common profile in Cayman) Do you continue to ascend directly to a safety stop at 15 feet (as required by tables) or do you hang out looking at the pretty fishies for another 20-30 minutes which is allowed by the computer??

 

[GLENFWB]

I have not commented on this thread till I read this quote. I am not sure if you are referring to the experience "after" getting DSC or the whole process? I took a DSC hit over two years ago. If I had it to do all over again....I know many things I would change and there are many things I HAVE changed since that time. I would never beat you up for the mistakes...most people who have been diving for any length of time have gotten away with a few stupid things. BUT I think accident analysis demands that we do things differently, otherwise we are "doomed to repeat it."

All in all, I didn't get the vacation I planned, but I got the vacation I needed. It may sound dumb and maybe borderline insane, but even knowing what I know now, I wouldn't change a thing.

 

[billgraham]

Do you know that you're describing a dive that requires precision depth control, gas management, relaxation, timing and ascent and decent speeds, that's marketed to people who can't stay off the bottom and many times "accidentally" end up on the surface or out of air?

flots.

Exactly.

Based on the requirements and scheduling posted for diving off the Canned Air, what would have prevented the same thing from happening to a diver there?

He wouldn't have been allowed to do the dive.

It is pretty standard on liveaboards to do 3-5 dives a day for 6-9 days or more. I am not as aggressive as I once was, but I have done ~22 dives in 5-1/2 days on the Palau Aggressor, ~28 dives in 7-1/2 dive days aboard the Undersea Hunter, etc. I can only recall one liveaboard (of 11) where I did less than 3 dives on a full dive day. There are usually divers aboard who do all the scheduled dives—basically 5 dives per full day on most of the boats I've been on.?

---------- Post Merged at 12:36 AM ---------- Previous Post was at 12:25 AM ----------

Just because it's "pretty standard" doesn't mean it's smart. I get that most pretty fish people don't have the training to understand why it isn't the greatest idea.

The rules that apparently exist in the northeast are not common to anywhere else in the U.S. or the world that I have experienced. I have never been required to have a redundant air source, reel, or liftbag on anything other than a tech dive.

As for three dives a day, it is extremely common throughout the world. People are doing 4-5 dives a day all over the world on liveaboards. People who go diving in resort areas very often do 3-4 dives per day. Your opinion is very clearly in the minority here, which is OK, but why would you be shocked to see it?

The dive the OP was describing is, or should be considered a tech dive and treated as such. Just about all the dives done here in Northeast are deeper than 100 feet so they are too. If you get on a boat without a reel, lift bag, backup gas, people will look at you funny at the very least, and most operators wouldn't let you dive like that. As for multiple days of multiple dives, everyone's free to do what they want obviously.

Look, you can all think I'm nuts, I don't care. What I see are open water divers, without much training taking a lot of risks. You've got the training to pull that off, but I think most others are flying blind. Why not get some training and be a little safer? It actually makes things more fun.

 

[vladimir]

I get that most pretty fish people don't have the training to understand why it isn't the greatest idea.

I have dived enough lumps in the sand masquerading as wrecks off Long Island to know that the big difference between you highly trained wreck divers and "pretty fish people" is that you guys can't afford airfare.

Make sure you're not overweight and make sure you wear your seat belts religiously, otherwise you're taking bigger risks than any DCS risk I have ever taken on a liveaboard.

 

[flots am]

Look, you can all think I'm nuts, I don't care.

The difference between paranoid and prudent is usually only apparent in hindsight.

flots.

 

[billgraham]

I have dived enough lumps in the sand masquerading as wrecks off Long Island to know that the big difference between you highly trained wreck divers and "pretty fish people" is that you guys can't afford airfare.

Make sure you're not overweight and make sure you wear your seat belts religiously, otherwise you're taking bigger risks than any DCS risk I have ever taken on a liveaboard.

Ha, funny. My two most recent dives were 1. SS. Oregon, Cunard Liner sunk 1886, 130 fsw, 500 something feet long. 2. San Diego, WWI cruiser, sunk 1918, 120 fsw, 500 something feet long and comes up off the bottom 50 feet. Hardly "lumps of clay". As for being overweight, I'll race you around either one. Oh, wait, sorry, you don't have the training to do the dive.

 

[vladimir]

Ha, funny. My two most recent dives were 1. SS. Oregon, Cunard Liner sunk 1886, 130 fsw, 500 something feet long. 2. San Diego, WWI cruiser, sunk 1918, 120 fsw, 500 something feet long and comes up off the bottom 50 feet. Hardly "lumps of clay". As for being overweight, I'll race you around either one. Oh, wait, sorry, you don't have the training to do the dive.

Nor the inclination. The Rhone, the Yongala, and Truk pretty much satisfied my curiosity for wrecks. And lots of pretty fish, of course. Here's one from the Fujikawa Maru:

I did a quick search and came up with an estimate for DCS cases on liveaboards from an AAUS conference at Duke in 1991.* It estimated a rate of <3 cases per 100,000 dives. It found "no particular evidence of unusual risk from multi-day repetitive diving as it is currently practiced within the recreational community." If you find that risk daunting I hope your blood pressure isn't high and you've had your colonoscopy.

*Yes, it's dated; I welcome any data you can provide that's more current.

 

[billgraham]

I'm not an instructor, MD, researcher, yada yada but most of the DCS incidents I've been unfortunate enough to be around happened after a second dive. I'm perfectly happy with accepting reasonable risks and my blood pressure is fine, tyvm. It's true that I rarely do recreational diving, but I did take a trip to Fiji last year for some pretty fish viewing. All of the dives were less than 80 feet, on air. I did them sidemount, spent a ton of time under the boat, and I still didn't like the way I felt after two dives. I didn't do three on any day. I know that I'm used to how I feel after diving the CCR (kind of like you never went in the water at all) and the difference was noticeable to me. We all spend a lot of money on dive trips and want to maximize our time in the water, but doing 3-5 dives a day for multiple days is putting your body through a lot, regardless of what the statistics say.

 

[vladimir]

I'm not an instructor, MD, researcher, yada yada but most of the DCS incidents I've been unfortunate enough to be around happened after a second dive. I'm perfectly happy with accepting reasonable risks and my blood pressure is fine, tyvm. It's true that I rarely do recreational diving, but I did take a trip to Fiji last year for some pretty fish viewing. All of the dives were less than 80 feet, on air. I did them sidemount, spent a ton of time under the boat, and I still didn't like the way I felt after two dives. I didn't do three on any day. I know that I'm used to how I feel after diving the CCR (kind of like you never went in the water at all) and the diference was noticeable to me. We all spend a lot of money on dive trips and want to maximize our time in the water, but doing 3-5 dives a day for multiple days is putting your body through a lot, regardless of what the statistics say.

Sounds like a great reason for you to avoid a lot of repetitive diving.

As an aside, having done a lot of trans-Pacific flying, I would not underestimate the effects of jet-lag on your sense of well-being. I have read that it takes one day per hour of time change to completely adjust, and my personal experience bears that out. So on a trip to Fiji you're completely adapted just in time to go home, usually.

 

[billgraham]

I'm just saying that the more dives you do in a day, the riskier it is. Doing it a bunch of days in a row is riskier yet. If something goes wrong (like you end up at 160 feet and make a fast ascent) there's far less margin for error, that's all.