Catalina Diver died today w/ Instructor

[Scott L]

Perhaps the valve was opened initially then inadvertently closed by someone who employed the antiquated quarter-turn back-off to extend life of $2 part (valve seat)...

 

[merxlin]

Unfortunately, most pros seem to adhere to the quarter turn back and unless it becomes standard practice to fully open valves, you run the risk at some point of someone helping you quickly without thinking. It is up to us to make sure we can reach our own valve and to check our valve ourselves before each splash.

Sorry, but if they are "pros" they should know which direction is on and which is off. If my air is off, I will know it by my own check, and will (although with some embarrassment) ask for you to turn it on. Been there, done that.

 

[drbill]

@drbill: Based on your report in Post #55 of this thread, the incident occurred while the instructor and student were descending on the south boundary buoy chain. It was reported earlier in the thread that the incident occurred during the initial descent. 14 minutes seems too long to be consistent with that. Was the class doing some skills or swimming along for a little while before descending to about 60 fsw? It sounds like the ascent occurred rather quickly (1-2 minutes tops).

I understand the confusion... I felt the same way when I heard the duration of the dive. It is possible my ears heard wrong or my brain processed wrong, but that is what I (think I) heard.

As to the possibility of a partially closed valve...
I was under the impression that if a valve were barely open then it might deliver some air (possibly with resistance) at shallower depths and provide no flow at greater depths. This would seem to be consistent with a scenario of OOA at depth (perhaps with a delay in signaling OOA) and the finding of sufficient quantities of gas upon retrieval of the diver's gear.

IF my recollection of the total dive time is correct, it is unlikely that the valve was not open sufficiently. If not, open to question.

 

[Scott L]

Sorry, but if they are "pros" they should know which direction is on and which is off. If my air is off, I will know it by my own check, and will (although with some embarrassment) ask for you to turn it on. Been there, done that.

That's not always the problem. Somewhat frequently inexperienced on-board crew will take it upon themselves to check valves when a diver may be busy assisting a buddy get into equipment, etc. Quite another senario involving myself occured wheras a 20 year dive instructor/charter captain checked my H-valve which operated in reverse order (Clock-wise to open) & consequently closed the valve before my rolling off side of boat. Thankfully my buddies darted right over to assist at about 20ft under when I motioned for assitance...With experienced divers this is the far more likely senario...

That's another reason not to back-off a quarter turn...Gives the illusion
of the valve being not fully open which it technically isn't....

 

[drbill]

By the way, I heard about the total dive time after I stated my initial understanding of the incident. I thought it sounded much longer than I anticipated but will try to verify that if I can.

 

[Thalassamania]

What do we know about the entire profile? A shallow out and then a drop down and then OOA would jibe with a partially open valve.

 

[bsee65]

By the way, I heard about the total dive time after I stated my initial understanding of the incident. I thought it sounded much longer than I anticipated but will try to verify that if I can.

Speculating, is it possible the instructor gave a briefing then descended to oversee the students' arrival at depth? She could have been in the water for 14 minutes with one or more of the students, including the victim, being down for a shorter period.

 

[drbill]

Thal and bsee65... can't speak to the total profile until the computers are evaluated. I know when I refer to total dive time, I refer to what my computer records and that requires a descent to about 5 ft to initiate. The problem is we are back in the realm of (relatively harmless) speculation. Maybe I can get some clarification on this.

 

[cruiser]

Turning the valve fully on also has the potential for the valve to "stick", even with newer type valves

Would a stuck valve present a problem if it was stuck open?

 

[Thalassamania]

Would a stuck valve present a problem if it was stuck open?

No ... problem would be when you went to shut it down to remove the reg.