The straw that broke the divers back.

[HowardE]

Beats me.

If there aren't any, then diving with any rebreather is a crap shoot.

Terry

That's a common opinion, but try breathing into a bag for 2 minutes, and see how bad you get a headache. Then... you bailout. That's CO2 monitoring.

 

[Web Monkey]

That's a common opinion, but try breathing into a bag for 2 minutes, and see how bad you get a headache. Then... you bailout. That's CO2 monitoring.

Sorry, counting on a headache to monitor breathing gas just isn't up to my safety standards.

Terry

 

[pdelannoy]

I thought the post by 116fire raises a valid point regarding the demographics of the diving population. Thanks for the post.

PD

 

[paddler3d]

The link was broken, but in all honesty - most diving related accidents are ruled drownings. The problem with diving is that people are in the water... Ultimately - they drown. The water does a good job of hiding the evidence.

In climbing, most accidents result in death due to trauma.

The the AMA looks at is the climbers skill and experience vs. the route they were climbing. Climbing partners are interviewed. Equipment is looked at. They go through at try and identify the actual cause of the accident and not the result. The result is obvious if the made it in the AMA publication.

For instance, something like 80% of climbing fatalities occurred on the way down by doing things like not tying a knot in the ends of their rappel rope and rappelling off the end of the ropes!

When you read a stat like that you realize that statistically you're not going to die on the way up and you need to keep your wits about you for that return trip, and trust me, as tired as you may be that 80% stat is in the back of your mind and you double check everything and make sure every foot placement and anchor placement.

The AMA has a narration for each accident. They don't give you sweeping stokes of 88 climber died between the ages of 45-52 in 2009 by falling (I'm speculating at that stat, purely fictional). They really try and look at the root cause.

That type of information would be very helpful for diving as well.

I tried the link and it works.

 

[Rhone Man]

Since you mention Hypercapnia. How would better fitness help there? It wouldn't at all.

Sorry Howard, not to be argumentative, but I spent last night reading through the DAN Tech Diving Conference report, and they actually list better physical fitness first on their list of recommendations for reducing hypercapnia risk.

EDIT: Sorry, my mistake, it was actually second to last on their list, but still: "Stay physically fit, which might help avoid respiratory muscle exhaustion.", see page 33.

http://www.diversalertnetwork.org/FastAccess/2008TechnicalDiving.aspx

 

[HowardE]

Sorry Howard, not to be argumentative, but I spent last night reading through the DAN Tech Diving Conference report, and they actually list better physical fitness first on their list of recommendations for reducing hypercapnia risk.

EDIT: Sorry, my mistake, it was actually second to last on their list, but still: "Stay physically fit, which might help avoid respiratory muscle exhaustion.", see page 33.

DAN Divers Alert Network

My friend... Certainly, better physical fitness isn't a bad thing for a lot of divers. How many divers are severely obese? (too many?) This is a problem for their life in general and not just diving... Maybe these people effect the curve, on how and why accidents occur. However; the reason for people having hypercapnia episodes whilst on a CCR is because of lack of due diligence. Packing the scrubber and checking the seals on that scrubber can is a BASIC TASK for CCR divers. It is your life support. These incidents with hypercapnia are not from people being fat, but from them making a basic mistake. Maybe that's harsh, but is it not true?

If I die from hypercapnia; you can say, "Howard really ****'ed up"

 

[Rick Murchison]

Indeed, a diver who is physically fit can process more fuel and produce more CO2 much faster than one who is not. On a rebreather that fit diver can overload a scrubber much faster than the diver who just can't exert as much effort.
'Course there are a whole host of other things that'll bite the unfit diver, but with a closed loop and scrubber, all other things being equal CO2 production is what'll cause excess CO2 in the breathing gas and resultant hypercapnia.
Rick

 

[Rhone Man]

If I die from hypercapnia; you can say, "Howard really ****'ed up"

I would never be that insensitive - I would say something polite like "Gosh, what a tragedy. Any plans for his equipment?"

 

[idocsteve]

Indeed, a diver who is physically fit can process more fuel and produce more CO2 much faster than one who is not. On a rebreather that fit diver can overload a scrubber much faster than the diver who just can't exert as much effort.

I think you have it backwards.

A fit diver will not exert as much effort as a diver who is out of shape/obese/not used to the physical work in ivolved in diving. Take two guys, one who is an athlete and one who is a couch potato and have them run a lap on the local track. Who's gonna be breathing faster when they make it back around?

The fit diver might not even break a sweat or breathe any more heavily than normal while in a crisis, the nonfit diver might be blowing through his air supply like there's no tomorrow. And for him or her, there's a good chance there won't be.

 

[CaboJim]

Thanks for the great thread.
I have been diving for 34 years. I'm 59, & work out 4-5 times a week.
I am telling you this because of the decline in fitness I see on dive boats.

More overweight/obese people are now calling themselves divers. The truth is that
they're a heartbeat away from having a heart attack or worse.

We all know that diving can become very stressful, very quickly, with changing conditions.

How many times have you been on a dive boat, looked around, & said to yourself, how lucky I am that my buddy is fit, & I don't have to dive with one who isn't?

With this being said, remember diving is not a sport, sadly.