Use a gag strap?

[lermontov]

im in a similar camp to stuart i use one because my unit has one and i did my training with one - but i also read the gag strap eases the stress on the jaw on a long dive- i haven't done more than a 90 min dive on my unit yet so i don't know if this is a big deal or not.
I imagine a hypercapnia episode would be a goods reason to have a BOV but how much time do you have before it gets to the point where you cant take the DPV out -surely if you recognise a build up then you have time to go OC

 

[doctormike]

Why would someone panic at hyperoxia? Flush it down
CO2 definitely induces panic! lol

U never heard of VENTID?

 

[rjack321]

im in a similar camp to stuart i use one because my unit has one and i did my training with one - but i also read the gag strap eases the stress on the jaw on a long dive- i haven't done more than a 90 min dive on my unit yet so i don't know if this is a big deal or not.

I actually bought mine because my lips leak and the loop gets pulled on my scooter. Fewer/no leaks and less loop tugging for sure. I've done a little over 5 hrs on mine.

I imagine a hypercapnia episode would be a goods reason to have a BOV but how much time do you have before it gets to the point where you cant take the DPV out -surely if you recognise a build up then you have time to go OC

Not really. It's hard to detect and once CO2 feedback gets going all reports say that removing the DSV is next to impossible. Some of the survivors of Co2 hit only did so because they surfaced (involuntarily) from shallow water.​

 

[rjack321]

U never heard of VENTID?

I'm irritable all the time though

 

[doctormike]

I'm irritable all the time though

Maybe you get less irritable when your PO2 spikes - watch out for that!

 

[rjack321]

Maybe you get less irritable when your PO2 spikes - watch out for that!

sounds very soothing

 

[stuartv]

im in a similar camp to stuart i use one because my unit has one and i did my training with one - but i also read the gag strap eases the stress on the jaw on a long dive- i haven't done more than a 90 min dive on my unit yet so i don't know if this is a big deal or not.
I imagine a hypercapnia episode would be a goods reason to have a BOV but how much time do you have before it gets to the point where you cant take the DPV out -surely if you recognise a build up then you have time to go OC

Even on a dive that is not very long. I did 5 dives in Lake Erie a week ago. I had taken the gag strap off and was just using the stock bitepiece with lip shield. The longest dive was only around 50 minutes. Nevertheless, I noticed a fair bit of jaw fatigue during my dives because it felt like I was having to maintain a grip on the bitepiece with my teeth, to keep it in my mouth.

A different bitepiece with longer bite tabs might alleviate that. Not sure.

 

[Stoo]

I'm an OC guy, but dive with a bunch of RB folks and I've never seen any of them use a strap.

 

[Brad_Horn]

In addition, worth reading Paul Haynes article, ‘Increasing the probability of surviving loss of consciousness underwater when using a rebreather’, page 253 https://www.spums.org.au/file/574/download?token=SLGDpN2q#page=59

Obviously all military rebreather divers either have a gag strap (or FFM) fitted to their units. And EN14143 certification calls for them to prevent divers drowning in event of becoming unconscious. Which is why OSELs ALVBOV and DSV has to be supplied with a retaining strap fitted as a default, in addition to it just being a simple and cheap safety feature to offer.

Most telling is likely the sheer number of recreational rebreather divers whom have been recovered drowned; with their DSV/BOV out of their mouth. http://www.deeplife.co.uk/or_files/RB_Fatal_Accident_Database_100725.xls

 

[doctormike]

Most telling is likely the sheer number of recreational rebreather divers whom have been recovered drowned; with their DSV/BOV out of their mouth. http://www.deeplife.co.uk/or_files/RB_Fatal_Accident_Database_100725.xls

Telling, but statistically meaningless, right? I mean, no matter what the cause of death, if there is no gag strap, chances are that the loop will be lost. I'm not arguing against a gag strap, as I mentioned I'm considering the risks and benefits of one myself, but this isn't an argument for using one...

So the question remains - how likely is LOC compared to other events where a gag strap might be a problem if you don't have a BOV?