Clogged orifice vs stuck solenoid

[broncobowsher]

My understanding is both are like a light switch. Just fine, a second later complete FUBAR.
Hypercapnia (CO2 hit) is the one you might feel coming on before it is too severe, if you are paying attention and know what you are looking for.

 

[kensuf]

My understanding is both are like a light switch. Just fine, a second later complete FUBAR.
Hypercapnia (CO2 hit) is the one you might feel coming on before it is too severe, if you are paying attention and know what you are looking for.

I toxed while undergoing a schedule 6 in a recompression chamber back in '97. I knew it was coming right before it hit, but there wasn't much time to react.

 

[Underwater Tourist]

My understanding is both are like a light switch. Just fine, a second later complete FUBAR.

I forgot who, but someone on SB had a tox accident near the surface and survived because he recognized what was happening, inflated his bcd, and then the surface support team did their job well.

There are also other mentions of people recognizing the o2tox in different threads (I wish I remembered more specifics)

Plus the guy who died in roaring river, looks like he started panicking right before the tox event, likely recognizing what was happening as he also knew the gas he was diving was way too hot.

 

[Underwater Tourist]

@rjack321 unrelated question, where is your profile pic taken?

You mentioned before its one of the largest known stalactites

 

[rjack321]

@rjack321 unrelated question, where is your profile pic taken?

You mentioned before its one of the largest known stalactites

It's the downstream passage in Chac Mool in MX taken around 2007. "Xix Ha Tunich" in Mayan, means drip water stone. The largest known underwater stalactite, it's about ~28m tall.

 

[Underwater Tourist]

Thank you, will add it to my bucket list.

 

[nadwidny]

You said in another thread that there is a report about what happened to you. Can we find that online somewhere?

It was supposed to be written up in DAN's Alert diver mag. Looks like it didn't make the cut. It was in some scientific journal but I don't know which one.

Basically I went hypoxic (always know your PO2 kids) at the end of a shore dive on my RB. (Almost) No notice- at least none that we were taught to expect. I was there, then I wasn't. Woke up in the back of an ambulance. 2 nights in the hospital.

I should write it up here on SB since the other report doesn't seem to be happening. Maybe this weekend.

 

[R80]

The difference is hypoxia is considered a "silent killer". You pass out and drown. Some will argue you might notice decreased loop volume but I dont buy that argument.

Certainly decreased loop volume shouldn't be relied on, but if you notice the loop volume has dropped without a corresponding change in depth it's definitely a good call to immediately check ppo2/fo2.

As for not buying the argument, what would stop you from noticing that there's insufficient gas in the loop to respire even though ppo2 is still in a consciousness-supporting range?

 

[berndo]

It was supposed to be written up in DAN's Alert diver mag. Looks like it didn't make the cut. It was in some scientific journal but I don't know which one.

Basically I went hypoxic (always know your PO2 kids) at the end of a shore dive on my RB. (Almost) No notice- at least none that we were taught to expect. I was there, then I wasn't. Woke up in the back of an ambulance. 2 nights in the hospital.

I should write it up here on SB since the other report doesn't seem to be happening. Maybe this weekend.

Wow, sounds pretty scary, you must have been out for quite some time. Glad to hear you made it out OK.

 

[berndo]

3) If the ccr is used for cave diving with avg depths of 20-30m, what would you rather have: a clogged orifice or a stuck solenoid (i.e which one is less dangerous)?

For that range I wouldn't buy a rebreather, unless you really want to dive for hours on end. In that range you can easily carry enough gas for a couple of hours.

When I picked a CCR I knew I wanted one with a HUD. I wouldn't wanna dive without one. I also wanted a decent water trap.
It's a wild guess, granted, but seems to me that getting distracted at the worng time is what caused the most ccr fatalities and HUD give you one more change to draw you're attention away from whatever you're distracted by.