Diver dies in San Diego

[Power Scuba]

On this board, or most others, very little is ever known, per se.

That's not correct The true nature of many accidents and incidents become known. Take the Donothan death in SD a few years ago for instance.

But please, conjecture and hypothesize away. I'll file it away where it belongs.

 

[nereas]

It's much easier for me and the mods if I just mute your posts, instead.

Which I have, as of now.

Rants don't accomplish much.

Introspection, on the other hand does.

 

[eponym]

As a matter of question, if you were down to just a few breaths/on empty and were deep when you realized it, would you use that last bit of air to inflate your bc to try and get you to the surface if you couldn't cesa from the depth you were at?

Fascinating question, and not one I've ever heard from a student.

On the face of it, my baser instincts would be to reserve that air for breathing. But since you can breathe out the air in your BC, maybe the smart money would be on parking it in the BC to ease the ascent until it's needed. However, research (including reports at DAN) on inflating BCs at significant depth is pretty gloomy--it's a slow and air-intensive approach.

Realistically, however, if I've been so dumb as to run out of air and out of buddies, I'm probably not going to notice that I'm very very low on air. I'm going to notice instead that I can no longer suck air out of my second stage: I'm "out". So the question of how best to use the last remaining air will probably be moot. In addition, I might well decide to drop weights and risk DCS.

I put "out" in quotes because as I ascend from "deep" (say 80 fsw) the reg will be able to deliver me another breath or three as the ambient pressure drops. At least that's the theory . . .

-Bryan

 

[dumpsterDiver]

As a matter of question, if you were down to just a few breaths/on empty and were deep when you realized it, would you use that last bit of air to inflate your bc to try and get you to the surface if you couldn't cesa from the depth you were at? I'd rather be unconscious and bent on the surface than at 20 feet.

I think this is an important question. I've been in a few very low air situations myself. Some people will say that you can do BOTH. Simply take a breath from the regulator and then exhale into the BC. Thus you have maximum benefit of breathing and then bouyancy when you really need it. It SOUNDS good but is not best in my opinion.

When you have very low air (have zero redundancy or donor options) and you are negative and absolutely need to begin an ascent, it is my firm opinion that the air is better spent going directly to the BC. I also would not try to swim up, Instead I will use the power inflator to inject the precious air directly to the BC to establish positive bouyancy and attempt to keep my body and especially my legs as still as possible. I think the task loading of trying to breath in and then orally inflate the BC during a real emergency will cause me excessive stress and therefore use MORE oxygen. It is more efficient to inflate the BC rather than try to swim up against a negative condition while breathing. Put simply, the little bit of air is better used in the BC than in your lungs.

If a diver can remain reasonably calm, they can probably get by on a reduced respiration rate for some time if it is a life or death situation. I will inflate the BC alot, get the ascent going, (probably fast like 60 feet per minute) and relax and try to sip my air (even if I feel air starved). This is much easier to do, if the diver is relaxed and simply riding the BC up. As I get closer to the surface, say 40-50 feet depth, I would be dumping air from the BC and really try to do a slow ascent from that point upward.

 

[divemedic1316]

In reference to the San Diego Lifeguards.......lack of vigilance. The SD guards are supposed to be some of the best in the world? Do they need to be spanked?

 

[nereas]

Fascinating question, and not one I've ever heard from a student.

On the face of it, my baser instincts would be to reserve that air for breathing. But since you can breathe out the air in your BC, maybe the smart money would be on parking it in the BC to ease the ascent until it's needed. However, research (including reports at DAN) on inflating BCs at significant depth is pretty gloomy--it's a slow and air-intensive approach.

Realistically, however, if I've been so dumb as to run out of air and out of buddies, I'm probably not going to notice that I'm very very low on air. I'm going to notice instead that I can no longer suck air out of my second stage: I'm "out". So the question of how best to use the last remaining air will probably be moot. In addition, I might well decide to drop weights and risk DCS.

I put "out" in quotes because as I ascend from "deep" (say 80 fsw) the reg will be able to deliver me another breath or three as the ambient pressure drops. At least that's the theory . . .

-Bryan

Well, a good instructor will first teach you to monitor your own SPG and also that of your buddy's periodically as well. The text manuals say every 5 to 10 minutes.

This would be plan A.

Let's say you did not pay attention in class, or else you did not have a good instructor, and now you are at 100 fsw and the needle of your analog SPG is on -0-.

A good instructor would have taught you to be neutrally buoyant at all times. And if you are, all you would need to do is kick up a little to begin your ascent. In a wetsuit, the wetsuit decompression would begin your propulsion upwards. From that point up, you would need to carefully bleed air from your B/C-wing to control the ascent. In a drysuit, you would also need to carefully bleed air to control it.

As you ascend, your ambient pressure would decrease, therefore even though your SPG read -0-, your regulator would be delivering more air/nitrox for you to breathe from your tank, since that is how the laws of physics work!

[Note: the laws of physics are not really "laws" but rather observations and conclusions, a form of opinion, by science professionals, who see these "laws" recurring continuously. Technically, to be a "law" something must be uttered by a king over a matter within his jurisdiction, which is the actual origin and definition of the ancient Persian word "law" which means "of the king," and that is how the word made its way into English.]

 

[nereas]

In reference to the San Diego Lifeguards.......lack of vigilance. The SD guards are supposed to be some of the best in the world? Do they need to be spanked?

How did the lifeguards end up with blame for this? Are they trained for rescues to 150 ft?

That is 3x my average freediving depth.

 

[Clammy]

You mean they aren't bay watch style super life guards?! Pssht. They need to come to Malibu and learn a few things from our life guards. Like how to come with your own flotation device!

 

[Rick Murchison]

In reference to the San Diego Lifeguards.......lack of vigilance. The SD guards are supposed to be some of the best in the world? Do they need to be spanked?

Absolutely not.
This mishap occured entirely under the water and was over by the time there was any indication of a problem on the surface.
In fact, nothing the lifeguards did or didn't do has any relevance to this mishap at all.
Rick

 

[crispix]

Put simply, the little bit of air is better used in the BC than in your lungs.

What about using it in both BC and lungs? Not that I'd ever want to try this, but couldn't the BC be used as a source of emergency air? Worst case scenario, OOO and ascending, how about sticking the oral inflator in your mouth, hold the purge button, and breathe out/in a few times? Yes, it would be nasty, recycled air, but that's better than breathing water.

Ugh.