Off with the BOV

Saying "I don't and or have have stopped using my BOV because I have not had an issue to use one" is like saying, I have not had a car accident so I don't think I need to put my seat belt on... :poke:

+1
Ramble: As DSO, from time to time, I get from my divers (and I have 110 of them) grumblings when I have to lay down the law with regards to gear, as "they've never had an issue with it in all they years they've been diving". It's never a problem... Until it's a problem.

Case in point... Many years back, when I took over this job, there was a volunteer diver who historically was allowed to dive with the Apollo bio-filter screwed into his first stage. This, in my personal opinion, was a bit if pure ****** kit - a 4" extruded aluminum tube, aka lever, sticking out of the side of your first stage and connection you to your air supply. Anyway - and my bad - I let him continue to use it as he was a long time vol and it was "grandfathered" in. Plus - "after all these years diving with it he's never had a problem. " (sarcasm)

Well, not two weeks in he was ascending from the bottom of an exhibit and he swam past an overhang and shore the damn thing off. 2nd stage in his mouth breathing nothing but water and a champaign bottle behind him - in front of the public. Needless to say I learned my lesson (the diver was fine, by the way). It's never a problem - until it's a problem.

By the way - my other favorite statement (but in the opposite way) is emergencies don't wait for training.
 
Originally Posted by Andra

Hi Colin,

I wonder if rEvo divers have less to fear?

I see the main reason for a BOV is CO2. Given that the rEvo has split scrubbers, I assume that the chance of breakthrough is much reduced.

On the other hand, i might be entirely wrong?!



I wouldn't like to partially flood one to test that..


I wouldn't want to partially flood any unit (Only ever flooded my Vision) but as said my main reason to have a bov would be Co2, if you flood the unit then you would not have the issue of Co2 preventing you getting off the loop onto a standard second stage bailout .
 
I wouldn't want to partially flood any unit (Only ever flooded my Vision) but as said my main reason to have a bov would be Co2, if you flood the unit then you would not have the issue of Co2 preventing you getting off the loop onto a standard second stage bailout .

A flooded scrubber usually makes the WOB goes through the roof. If the diver were to stay on his unit with a flooded scrubber, I suspect that the chances of a CO2 hit also rise dramatically. Obviously, some units are more susceptible to flooding than others and depending on the design, some scrubbers will continue to provide a reasonable WOB even with a partial flood.
 
A flooded scrubber usually makes the WOB goes through the roof. If the diver were to stay on his unit with a flooded scrubber.

Agreed it would go through the roof BUT you should have noticed before that point. If the diver stayed on the unit with a flooded scrubber then he is an idiot or was diving alpinist in which case was prepared to accept the risk
 
If the diver stayed on the unit with a flooded scrubber then he is an idiot or was diving alpinist in which case was prepared to accept the risk

That may well be the case, but that said, I have seen a good portion of people on the forums reporting CO2 hits over the years due to floods.
 
That may well be the case, but that said, I have seen a good portion of people on the forums reporting CO2 hits over the years due to floods.

on one of the other threads running at the mo , co2 gets tossed in as the problem . along with 20 other thing.s. problem with co2 reporting , half the time its just no the problem ,

seems your not a real ccr diver till you have had a co2 , lol .
 
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That may well be the case, but that said, I have seen a good portion of people on the forums reporting CO2 hits over the years due to floods.

That's an interesting thought. I found the stack in my Sentinel was often damp and the OPV pot sometimes had a little free water in it though never sufficient to warrant having to perform a flood recovery procedure. This certainly never gave rise to a CO2 hit. Have any Sentinel owners who have had to perform a flood recovery and therefore had soaking wet lime had a consequential CO2 hit? Now I dive a JJ and the lime stays bone dry as presumably the water trap in the exhale tee-piece is very efficient. Of course, now I am using a FFM, damp lime or a flood is even less likely.
 
Seeing other units BOV, I can certainly understand why you remove it. As well for free flowing arguments if Regulator is placed in the front. I like my Poseidon BOV. It is compact and light, It isn't prone to freeflow and it is real easy to go OC. However, I just installed a shutoff valve to be able to close the gas in case of any issues with it. It is conveniently placed just between the BOV and the hose.
 
That's an interesting thought. I found the stack in my Sentinel was often damp and the OPV pot sometimes had a little free water in it though never sufficient to warrant having to perform a flood recovery procedure. This certainly never gave rise to a CO2 hit. Have any Sentinel owners who have had to perform a flood recovery and therefore had soaking wet lime had a consequential CO2 hit? Now I dive a JJ and the lime stays bone dry as presumably the water trap in the exhale tee-piece is very efficient. Of course, now I am using a FFM, damp lime or a flood is even less likely.

The Sentinel is an interesting study in flood recovery because as you perform a dil flush, the gas goes through the scrubber and out the bottom OPV. Theoretically, you should get some drying of the sorb during the process.
 
Hey Peter, I can understand your reasoning if it's not doing what you want it to and it's not reliable. The whole point behind any piece of backup equipment is it has to work if needed and you have to trust it will work and work well. There are other BOVs out there and I'm sure there is one you'll feel comfortable with and you'll like.

I have seen many divers buy a piece of equipment and bolt it on, not fully understanding what is involved only to remove it later. Yes, anyone can fit a BOV but do you know what options you have and why you've done them.......Probably not.

The deeper you go the more likely a BOV will save you where a second stage may not but it's all about practicing emergency drills, meticulous planning, servicing and equipment familiarity. Not long after I bought my Drager FFM I had enough of it and decided it was time to get rid of it but after diving without it I found I actually preferred it. Now I really, really don't like diving without it......

Regards,

Lance
 
The Sentinel is an interesting study in flood recovery because as you perform a dil flush, the gas goes through the scrubber and out the bottom OPV. Theoretically, you should get some drying of the sorb during the process.

I think "drying" may be a little optimistic. More like 'less wet'... :chuckle:
 
That's an interesting thought. I found the stack in my Sentinel was often damp and the OPV pot sometimes had a little free water in it though never sufficient to warrant having to perform a flood recovery procedure. This certainly never gave rise to a CO2 hit. Have any Sentinel owners who have had to perform a flood recovery and therefore had soaking wet lime had a consequential CO2 hit? Now I dive a JJ and the lime stays bone dry as presumably the water trap in the exhale tee-piece is very efficient. Of course, now I am using a FFM, damp lime or a flood is even less likely.

I've flooded the Sentinel with a counterlung split at the seam (which passed the negative test), attempted flood recovery through bottom of cannister which was only partially successful (due to user being out of practice on this skill and at the 6m stop so concerns about putting too much buoyancy into the lung), completed 30 mins deco with about 1L water still left in the bottom of the can (I poured it out into a 2l coke bottle and it looked about half full), no CO2 symptoms.

I killed the TPM cable but other than that, a bit of a dry out and fix the counterlung with superglue, and it was good to go again that afternoon.

To the OP's question, I got a JJ with a DSV, after about a year I fitted a Shrimp BOV, and I won't be taking it off again.

Tb.
 
Hey Peter, I can understand your reasoning if it's not doing what you want it to and it's not reliable. The whole point behind any piece of backup equipment is it has to work if needed and you have to trust it will work and work well. There are other BOVs out there and I'm sure there is one you'll feel comfortable with and you'll like.

I have seen many divers buy a piece of equipment and bolt it on, not fully understanding what is involved only to remove it later. Yes, anyone can fit a BOV but do you know what options you have and why you've done them.......Probably not.

The deeper you go the more likely a BOV will save you where a second stage may not but it's all about practicing emergency drills, meticulous planning, servicing and equipment familiarity. Not long after I bought my Drager FFM I had enough of it and decided it was time to get rid of it but after diving without it I found I actually preferred it. Now I really, really don't like diving without it......

Regards,

Lance

Gee Lance, could you possibly be more patronizing ?

Peter
 
I've flooded the Sentinel with a counterlung split at the seam (which passed the negative test), attempted flood recovery through bottom of cannister which was only partially successful (due to user being out of practice on this skill and at the 6m stop so concerns about putting too much buoyancy into the lung), completed 30 mins deco with about 1L water still left in the bottom of the can (I poured it out into a 2l coke bottle and it looked about half full), no CO2 symptoms.
Did it also pass a positive test?



Sent from my iPhone using Tapatalk
 
Did it also pass a positive test?



Sent from my iPhone using Tapatalk

Tricky to do positive test on a Sentinel since it has OPV on the bottom of the scrubber cannister, which is not accessible after the unit is assembled.

So I found that with the OPV set right for me in dive mode, it was too 'loose' to hold pressure for a pos test.
 
I used to back off my Sentinel OPV valve by five clicks and it held a positive fine. Alternatively you could just cap the exhaust hose with your thumb for a minute or two.
 
I used to back off my Sentinel OPV valve by five clicks and it held a positive fine. Alternatively you could just cap the exhaust hose with your thumb for a minute or two.

Capping the hose would work I imagine.


Sent from my iPhone using Tapatalk
 
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