Reason for near miss in Mexico???

[CrawfishDiver]

WOW still alittle concerned about the 20ft thing leaving your buddy 20 ft is a long ESA if you exhale and then can't inhale again. Holding breath at 20fsw again bad Idea. surface conditions can cause a large change in pressure with little movement on your part. Glad your ok reminds me why i go over hand signals and air share with my ready made buddies on dive boats.

 

[Mossman]

WOW still alittle concerned about the 20ft thing leaving your buddy 20 ft is a long ESA if you exhale and then can't inhale again. Holding breath at 20fsw again bad Idea. surface conditions can cause a large change in pressure with little movement on your part. Glad your ok reminds me why i go over hand signals and air share with my ready made buddies on dive boats.

If someone has exhaled, is there enough residual air to cause an overexpansion injury from a breath-hold ascent from 20 FSW?

At the resting expiratory level, the volume of air in the lungs is equal to the functional residual capacity of approximately 2300 ml. The inspiratory reserve volume is approximately 3000 ml. Therefore, even a doubling of the functional residual capacity (i.e. a breath-hold ascent from 33 FSW) shouldn't exceed the inspiratory capacity, making an overexpansion injury in the situation described ("20 ft is a long ESA if you exhale and then can't inhale again") very unlikely.

 

[Mossman]

Swimming hard and being excited at 20 ft. could still cause sudden loss of consciousness from a CO2 tox if the reg. failed in a manner that made breathing difficult. Continuing the dive (even at 20 ft.) after breaking up the team was the wrong strategy. I could make comments about foreign rental gear too, but these are self-evident.

Sudden loss of consciousness from a CO2 tox? Yikes! That sounds scary!

Do you know how much CO2 the diver would have to build up in order to lose consciousness? It ain't gonna be "sudden". He's gonna feel all sorts of reasons to want to ascend well before that point.

Try an experiment sometime, with a buddy or even an entire team: breathe from a rebreather with an empty absorbent cannister but with sufficient O2. See how long it takes you to lose consciousness and how you feel in the meantime.

On the other hand, if there were nothing to see at 20', and often there isn't, then I'd surely abort the dive.

I've used some fine foreign rental gear and have witnessed people having serious problems with shoddy U.S. rental gear. Are you xenophobic?

 

[LAJim]

I don't rent gear anywhere. Check other threads in this forum and you might draw conclusions about rental gear and safety standards in some countries relative to the US.

I'm not afraid of xenon or any of the other noble gases. Fluorine is pretty scary and I've had traumatic experiences with some of the Group 1 elements, so maybe I'm kaliphobic or even natriphobic.

 

[Mossman]

I don't rent gear anywhere. Check other threads in this forum and you might draw conclusions about rental gear and safety standards in some countries relative to the US.

I know better than to draw conclusions from anecdotal evidence.

What would you do if you found yourself on an expensive dive trip to a foreign country and your reg failed in a manner that couldn't be fixed locally. Assuming that no one in your team had a backup reg, would you rent one from the foreign country or would you sit out the rest of the trip?

 

[LAJim]

1. I'd use my back-up. If that failed too, then I'd

2. Sit. Maybe check the terms of my travel insurance to see if I had a basis for a claim.

3. While sitting I'd think about the problem posed in this thread before it got off-topic and chill.

 

[Divingdon]

Hmm, what did the dive centre use to show that the tank was full? If it was tape, I'd guess you didn't remove the tape before the dive.

 

[ShakaZulu]

What would have happened if your were over weighted and could not stay on the surface.......sounds to me like you want to become a statistic. Even worse since you had time to think about your actions.

 

[mislav]

What would have happened if your were over weighted and could not stay on the surface.......sounds to me like you want to become a statistic. Even worse since you had time to think about your actions.

Orally inflate your BC and ditch the weightbelt. Not necessarily in that order.

 

[Ed Hatfield]

May I recommend the book 'Diver Down', by Michael R. Ange, Technical Editor, Scuba Diving magazine. The book is published by McGraw Hill. Without question LAJim is right - the dive should have been aborted. You are probably luckier than you may realize.