Use a gag strap?

[silent running]

I've seen two people get CO2 hits. Both took awhile to clear up after they bailed out. They both chewed through a LOT of gas. More so than they would have thought possible before they took the hit.

I think the record was the guy that used over 40 cubic feet of gas to go 200' out in a cave with high flow.

Yes, I understand that complete relief from hypercapnia is not quick, just trying to find out if your diver friend tried the BOV/OC before you gave him the BO regulator. The more details the better regarding hypercapnia events such these as the onset is so quick and hard to detect beforehand. It would be very helpful to know whether he tried the BOV and whether it helped or not...

 

[kensuf]

Both cases, bailed out, both never went back on the loop. I'm completely unclear of what you're trying to figure out because I'm a believer that when you have a suspected CO2 hit, you don't go back on the loop.

 

[doctormike]

He's trying to figure out if the diver bailed out with a BOV or bailed out by going directly to an OC regulator. That's actually useful information, since we don't have a lot of details about hypercapneic episodes in general, so it's helpful to have details. One of the arguments for a BOV with or without a gag strap is that with a CO2 hit, you may be able to throw a BOV switch but not switch to a regulator.

But BOV or OC reg, both situations are bailed out, off the loop.

 

[silent running]

Both cases, bailed out, both never went back on the loop. I'm completely unclear of what you're trying to figure out because I'm a believer that when you have a suspected CO2 hit, you don't go back on the loop.

Sorry if what I wrote is unclear, but now I’m even more unclear about the order in which things happened.

drmike understood my question correctly; I’m asking if your diver friend used his BOV on the OC setting first before being assisted and given the regulator from his BO cylinder. If you switch a BOV to the OC setting you are in fact off the loop because the loop is then closed and you are now breathing OC gas directly and exhaling into the water, just like any other second stage. I’m asking if your hypercapnic friend had enough presence of mind to switch to the OC side of his BOV first, or was he so out of it that he could not even do that, and the first OC gas he received came from his BO cylinder second stage which someone forced him to take after closing his loop on the BOV.

This is a very interesting detail to me as I’m sure it is to anyone else following the story. If someone is so out of it from hypercapnia that they can’t even flip the lever on their BOV to get fresh gas and were only saved from serious injury/bolting to the surface because multiple people had to help switch and then remove the BOV from their mouth without the diver ever taking a breath from the OC side of the BOV, before being forced to take their BO regulator into their mouth, that’s the worst story of hypercapnia disability I’ve ever heard of. If that’s what happened and the diver never even tried to get an OC breath from the OC side of his BOV, this would call into question whether BOV’s can function as intended to save oneself, and indeed whether some people could even survive a hypercapnia event on their own without assistance from a team.

I’m asking as a diver who has a very good BOV that I’ve never had to use, and now I’m wondering if it is just another expensive gadget that could get me killed from the false idea that I could save myself from a hypercapnic event...

 

[doctormike]

The most important sentence in medicine is "there is a bell curve for everything".

So sure, there are probably some situations where the diver is so out of it that they couldn't throw a BOV switch themselves. But the advantage of the BOV is that it lets someone else bail you out if you are incapacitated, which really can't be done safely with a DSV.

 

[JonG1]

Plus you may get lucky and detect the signs and symptoms depending on the nature of the event and bail earlier because its easier to do so.

Brett Hemphill also advocated a half an half approach via a BOV in one of his vids, so you may come completely off initially due to some cues that could suggest hypercapnia but then after verifying your circumstances and deciding it probably isn't the loop that caused the cues, the BOV allows a slow and gradual transition back to it, with a known clean gas.

 

[silent running]

The most important sentence in medicine is "there is a bell curve for everything".

So sure, there are probably some situations where the diver is so out of it that they couldn't throw a BOV switch themselves. But the advantage of the BOV is that it lets someone else bail you out if you are incapacitated, which really can't be done safely with a DSV.

Yes, and a BOV with a gag strap gives someone else additional leverage and stability to BO assist the diver. My BOV OC/CC lever is spring loaded so it’s even easier to actuate.

I’d still like to know exactly who did what and in what order in Kensuf’s scary story...

 

[rjack321]

I’d still like to know exactly who did what and in what order in Kensuf’s scary story...

Bailed to the BOV with hypercapnia
Sucked through all the gas plugged into the BOV
Needed still more of buddy's deep OC gas via a 2nd stage before finally stabilizing

(I don't know for sure but putting in my bets now)
@kensuf am I close?

 

[kensuf]

Sorry if what I wrote is unclear, but now I’m even more unclear about the order in which things happened.

<snip>

I’m asking as a diver who has a very good BOV that I’ve never had to use, and now I’m wondering if it is just another expensive gadget that could get me killed from the false idea that I could save myself from a hypercapnic event...

got it..

Situation 1 - Diver coming up from a 300' dive. Bailed out to BOV at about 180', but then switched to other OC gases as we got shallower (deco gases/etc). His BOV was plumbed into a 3L cylinder so it wouldn't have lasted too long anyway (we had about an hour of deco).

Situation 2 - Diver on a cave dive. Bailed out on BOV and stayed on BOV for the 200' travel to the exit. For those of you familiar with the cave, he was at the Park Bench in Ginnie. His BOV was plumbed into off-board gas and he had all the gas in the world; it was literally the start of a cave dive and he CO2'd himself by swimming too hard in the flow.

BTW now that I'm thinking about it, there's two more events I can think of. Both involved debris in mushroom valves (duckweed). Both cases divers stayed on the BOV, both cases the BOV was plumbed into off-board gas.

 

[rddvet]

got it..

Situation 1 - Diver coming up from a 300' dive. Bailed out to BOV at about 180', but then switched to other OC gases as we got shallower (deco gases/etc). His BOV was plumbed into a 3L cylinder so it wouldn't have lasted too long anyway (we had about an hour of deco).

Situation 2 - Diver on a cave dive. Bailed out on BOV and stayed on BOV for the 200' travel to the exit. For those of you familiar with the cave, he was at the Park Bench in Ginnie. His BOV was plumbed into off-board gas and he had all the gas in the world; it was literally the start of a cave dive and he CO2'd himself by swimming too hard in the flow.

BTW now that I'm thinking about it, there's two more events I can think of. Both involved debris in mushroom valves (duckweed). Both cases divers stayed on the BOV, both cases the BOV was plumbed into off-board gas.

Is Diver 1 reconsidering being plumbed into a 3L after that?

Out of curiosity, how would you know during the dive if your mushroom valve is being affected by debris? We talked alot about the mushroom valves in class, sepcifically with checks during setup and what would happen if there's an issue. What would be the symptom to watch for if when getting in at Orange Grove you get duckweed into a mushroom valve?