rEvo BOV

cathal said:
Just wondering has anyone heard any of developments regarding a rEvo BOV



Cathal
Click to expand...



Just get a Shrimp the QDs are great & it works well

Paul doesn't see any urgancy with BOVs it seems.

An attitude which baffels me but some seem to think a BOV is unnessasary


ATB

Mark
 
Mark Chase said:
Just get a Shrimp the QDs are great & it works well

Paul doesn't see any urgancy with BOVs it seems.

An attitude which baffels me but some seem to think a BOV is unnessasary


ATB

Mark
Click to expand...

I just got rid of mine ;)




Sent by my rEvo scrubber using a shearwater Nerd
 
Mark Chase said:
Just get a Shrimp the QDs are great & it works well

Paul doesn't see any urgancy with BOVs it seems.

An attitude which baffels me but some seem to think a BOV is unnessasary


ATB

Mark
Click to expand...

It equally baffles me that some are convinced that a BOV is such a benefit.

There we go, we're both baffled. I'm sure if we try we can achieve perplexed, puzzled, bemused and maybe even flummoxed.
 
Baron015 said:
I am perplexed, confused, confounded non-plussed and disconcerted that you would dive without a BOV !
Click to expand...

I am comfortable, at ease, relaxed, unworried, contented and ultimately happy with your reaction to my stance on the much vexed question of the BOV.
 
I had a BOV on my rEvo.
I removed it mainly due to its drag when scootering. I dont miss it.
Nor do I miss the wart I had on my knee when I was a young kid.
 
I dont ware a crash helmit any more.

They are expensive, uncomfortable and hot.

I havent fallen off my bike for over 20 years so I simply cant see the point in them


Think ill get rid of my BOV too.


Actualy perhaps not, that would be a bit stupid dieing from a C02 hit just because I couldn't get on my bailout ;)

ATB

Mark
 
Mark Chase said:
Just get a Shrimp the QDs are great & it works well
Click to expand...
Mark, The rEvoIII has pretty good WOB as supplied with its modified Drager DSV. Almost as low as a Mk15.5
Have you worked out how much you would be increasing the rebreather WOB by, with the substitution of a Shrimp BOV?
 
Brad_Horn said:
Mark, The rEvoIII has pretty good WOB as supplied with its modified Drager DSV. Almost as low as a Mk15.5
Have you worked out how much you would be increasing the rebreather WOB by, with the substitution of a Shrimp BOV?
Click to expand...


No I dont have access to an Ansti macheen

However sufice as to say I havent had any noticable issue with the WOB of the Shrimp on the rEvo or JJ

I reely noticed the issue with the MK1 Golum BOV which was dangerously crap

I baught a low work of breathing kit for the MK1 golum BOV which made it tolerable

I was told by a CCR manufacturor i trust (but dont have data to back it up) that the JJ bov was 100% better than the MK1 Golum and 50% better than the MK1 Golum with LWOB kit.

I could easily beleive that from diveing them.

I was told the JJ BOV was about 20% better then the Shrimp which i could also beleive but frankly couldent notice on an actual dive but I know for sure the JJ BOV was crap as an OC reg and the Golum BOV was OK as an OC reg

If you have hard data, then great. But from just breathing them I can say the Shrimp seems OK

As you know i have dived the APOC BOV which is also great asnd I am told better than the Shrimp which I again can beleive but couldent quantifie on an actual dive.

If the APOC BOV were available in left / right & right / left flow id happily recomend it.

PS my rEvo was a non CE one but had the LWOB upgrades.

ATB

Mark
 
People fall of motorbikes all the time. Some of them die. If they didnt there would be no need for helmets.

How often do rEvo divers get CO2 hits? How many of them are injured or die form it?

Now weigh that against the increased chance of getting a CO2 hit due to increased WOB when using a BOV. Plus the increase in drag when scootering adding to jaw fatigue.

To be honest, if I didnt have a scooter I would still have a BOV (maybe). But I certainly dont miss it.
 
Mark Chase said:
I dont ware a crash helmit any more.

They are expensive, uncomfortable and hot.

I havent fallen off my bike for over 20 years so I simply cant see the point in them


Think ill get rid of my BOV too.


Actualy perhaps not, that would be a bit stupid dieing from a C02 hit just because I couldn't get on my bailout ;)

ATB

Mark
Click to expand...

Well you do seem very confident that a BOV will get you "outta dodge" so to speak. Great, more power to you. Just make sure that with every "decrease in objective danger" you don't increase the riskiness of your behaviour. I've certainly been guilty of that. There's a bit of evidence that risk compensation has been observed with cycling and helmets both by riders and by motorists, the riders being more reckless and the motorists not being so concerned about their actions around riders.

You do hear folk saying that a BOV decreases their fear of getting a CO2 hit. They think they can just "flip" the BOV and they'll be fine. Seems over confident to me. Over confidence: in the quality of the BOV, that the BOV itself won't be the cause of the hit due to high WOB, it's ability to supply the quantities of gas needed and an over confidence that whatever complicated method of getting gas from the big tins to the BOV isn't going to cause problems. Or, in the case of those who think its an intermediate step to off board OC, that they'll have reduced their breathing rate sufficiently by the time they're forced to go off the BOV.

I have read that elevated CO2 levels have other quite insidious effects at a psychological level with dramatically decreased cognitive functions. Have a read of a paper titled "Is CO2 an Indoor Pollutant? Direct Effects of Low-to-Moderate CO2 Concentrations on Human Decision-Making Performance" it's in the public domain. I mention this because I think taking as many steps as possible to avoiding High CO2 levels is more valuable, it's not just a high breathing rate to be concerned about, it seems the ability to make good decisions is one of the first functions that gets compromised. So for me, Low WOB on the RB, DPV, Tx etc is where I put my trust.

I am only referring to my reasons for not BOVvering with a BOV, you could of course be correct in recommending the use of them but I just don't see any evidence that they are a real solution.
 
Last edited:
I've mentioned it before, but the advantage of the BOV to ME, is way before you need to switch to it in anger. I use BOV to flush my loop and lungs of excess CO2 after strenuous periods during my dive (hard swim into the current, working out the anchor, etc..)
I flip to OC for few breaths, then switch back to CC. I certainly was not doing that with the reg, as it was too much bother to do.
I also used it during few complete floods of various units, very handy. :)

I also used to bike without a helmet. Since I started wearing them I had split two during hard falls. Glad that it was not my skull.
 
Packhorse said:
People fall of motorbikes all the time. Some of them die. If they didnt there would be no need for helmets.

How often do rEvo divers get CO2 hits? How many of them are injured or die form it?

Now weigh that against the increased chance of getting a CO2 hit due to increased WOB when using a BOV. Plus the increase in drag when scootering adding to jaw fatigue.

To be honest, if I didnt have a scooter I would still have a BOV (maybe). But I certainly dont miss it.
Click to expand...


If WOB issues from BOVs were causing C02 hits I think we would have noticed by now.

I have been in the water with two C02 hits

1: Was holding his bailout reg in his hand but simply couldn't switch to it and insted (beleiving he was going to die) he hit his wing inflate button and shot to the surface in 8 seconds.

2: Bailed out to a BOV at 69m totaly emptied his AL80 deep bailout and said switching from his AL80 trimix to the 50% tin was the hardest thing hed ever done. He litraly couldent do it til the reg went tight on the deep bailout. He was just staring at the OC reg knowing what he had to do but unable to do it.

Those two sotories alone are enough for me to use a BOV let alone all the others floating about on the net.

Some people say OH I had a C02 hit and I swaped regs easy? OK fine maybe in some instances you can maybee the hit was small or possably not even a Co2 hit at all it just felt like it could be one.

WHat ever the case I know for the small amount of hassell a BOV presents to me Ill never dive a CCR without one.

I owe that much to my kids

ATB

Mark
 
silentbob said:
Well you do seem very confident that a BOV will get you "outta dodge" so to speak. Great, more power to you. Just make sure that with every "decrease in objective danger" you don't increase the riskiness of your behaviour. I've certainly been guilty of that. There's a bit of evidence that risk compensation has been observed with cycling and helmets both by riders and by motorists, the riders being more reckless and the motorists not being so concerned about their actions around riders.

You do hear folk saying that a BOV decreases their fear of getting a CO2 hit. They think they can just "flip" the BOV and they'll be fine. Seems over confident to me. Over confidence: in the quality of the BOV, that the BOV itself won't be the cause of the hit due to high WOB, it's ability to supply the quantities of gas needed and an over confidence that whatever complicated method of getting gas from the big tins to the BOV isn't going to cause problems. Or, in the case of those who think its an intermediate step to off board OC, that they'll have reduced their breathing rate sufficiently by the time they're forced to go off the BOV.

I have read that elevated CO2 levels have other quite insidious effects at a psychological level with dramatically decreased cognitive functions. Have a read of a paper titled "Is CO2 an Indoor Pollutant? Direct Effects of Low-to-Moderate CO2 Concentrations on Human Decision-Making Performance" it's in the public domain. I mention this because I think taking as many steps as possible to avoiding High CO2 levels is more valuable, it's not just a high breathing rate to be concerned about, it seems the ability to make good decisions is one of the first functions that gets compromised. So for me, Low WOB on the RB, DPV, Tx etc is where I put my trust.

I am only referring to my reasons for not BOVvering with a BOV, you could of course be correct in recommending the use of them but I just don't see any evidence that they are a real solution.
Click to expand...



1: 1000s of BOVs out there and no evidance of C02 hits related to them?

2: Turning a knob on a BOV is IMHO less of a mental chalange than selecting the corect bailout tin and deploying and inserting a OC reg

3: My convoluted conection to 10ltr off board gas is a 1.5m regulator hose same as on my OC regs

4: BOV is tested in water begining of every dive, how often do you check your OC bailout regs

5: My OC bailouts are draged through the shit on the dive, my BOV is in my mouth which do you consider more likley to have an issue?

6: FACT you are more likley to bailout early on a BOV as it is such a simple task. Choosing to deploy an OC reg and re stow it if you go back on loop is far more of a chalange and as a result you will be less inclined to do it untill the situation becomes more serious

7: If you spit the CCR loop an go OC in a high stress situation you are far far more likley to flood the CCR rendering it useless and a burden for the ascent. If your attempt to go OC failes and you need to get back on loop its not a simple issue of twisting a knob and under now massive stress you could fail to acheive this manouver (see the report on Pennys Glovers death as an example of an aborted OC bailout and attempt to get back on loop)


I looked at the issues and made a decision. The only negatives I can find with a BOV is weight in the mouth, drag and cost None of which id argue against but none of which outweigh the advantages IMHO


I wont convince the nay sayers and I am not trying too. I just offer my thaught process for my decision.



ATB

Mark
 
kwinter said:
Can we all pitch in and buy Mark a dictionary? Or typing lessons?
Click to expand...

I am dyslexic they wont help

I apolagise for the anoyance but cut pasting and spell checking is too much of a pain when I am trying to get a responce out whilst I reely should be working :D

ATB
 
You must log in or register to reply here.
Back
Top