rEvo BOV

Back to the OP :-
Paul at rEvo told me years ago that he had the drawings on computer for a BOV but he didn't see a need for it. He states on the website that a Bov will be available end 2009 :-

http://www.revo-rebreathers.com/uploads/productenitems/flyer_rEvo_combine_en_2009.pdf Bottom of page .

See here for his response to that point being raised at the beginning of this year :-

http://www.ccrexplorers.com/showthread.php?t=17944&highlight=


Now I dive a rEvo & have done since 2009 & touch wood have not had a CO2 hit on the rEvo BUT I did have one on a Vision & I had a BOV but I still found it hard to switch to OC so can only imagine how hard it would have been to switch to an OC reg .
Genuinely I think there is a false sense of immunity within rEvo divers due to having 2 scrubbers & thinking " how can I screw up packing 2 scrubbers ? " Also some have blind faith in the RMS pushing scrubbers to their absolute limit.
On a personal level I have tried a Shrimp BOV on my rEvo twice now & really didn't like it because of the bulk etc but there again I find diving with a DPV extremely stressful as well which is why I am selling mine !
As Mark says it is all about personal choices.
 
Mark Chase said:
I wont convince the nay sayers and I am not trying too. I just offer my thaught process for my decision.



ATB

Mark
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C'mon Mark, we need to resist this false dichotomy of believers and heretics.

I am not a "nay sayer". I am (like yourself) a thinking diver. I have (like yourself) put a lot of time into deciding whether or not to use a BOV. I am yet to hear a case for a BOV that doesn't also have drawbacks.

In answer to your questions:

1000s of BOVs in use offers no evidence that they are effective.

The convenience of "turning a knob" is all very well, so long as the ability to ventilate is adequate and so long as the gas supplied to the BOV is a safe gas, I would argue (in the case of gas block set ups or multiple whips to be connected on the fly) that there is a higher risk of being supplied the wrong gas.

I test my OC regs at the start of every dive thanks for asking :) , and I test them periodically during a long dive. I don't drag them through the shit so feel confident they will work.

You claim it's a fact that BOVs encourage early BO, how do you know this? If it's just opinion then fine but you are claiming it as fact. My opinion is that a BOV might encourage a false sense of security due to the oft touted ability to "just flick it to OC and have a few breaths"* . This could then in turn encourage a return to a loop that for some reason (one you clearly thought good at the time) you just bailed off, this is where the insidious effect of high levels of CO2 making you dumb comes in. I would argue that if you find it a pain to swap between OC and CC then good. Get the loop and stay off, it's time to thumb the dive if you felt like you needed to BO.

If there was BOV that made no difference to CC WOB, had OC WOB as good as an OC reg, that didn't rely on fiddly (and sometimes highly unreliable) connectors and I was confident that the presence of a BOV wasn't going to increase my appetite for risk then I'd have one again.









*A few breaths?? really with elevated CO2 levels? How long does it take blood to get round the body? a minute or so? Doesn't that mean the "a few breaths" is more like a few minutes? (I think there must be a few on this forum who know the answer to this)
 
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silentbob said:
The convenience of "turning a knob" is all very well, so long as the ability to ventilate is adequate and so long as the gas supplied to the BOV is a safe gas, I would argue (in the case of gas block set ups or multiple whips to be connected on the fly) that there is a higher risk of being supplied the wrong gas
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My counter argument would be that no matter how bad the WOB might be or what breathing gas is connected, it is better than the alternative of trying to breathe water.

1. In case of a serious CO2 hit, you will not be able to get the DSV out of your mouth to switch to a second stage.
2. The convenience of turning a knob COULD lead to earlier and safer bailout.
3. Even if the wrong gas is connected, you can sort that out once you are breathing. But if you have the wrong gas connected and also have to bail out, you are having a really bad day.
 
To me it seems that some feel that CO2 hits come from out of the blue like a rock falling from the sky.

I too have had the experience of being on hand when another diver experienced a CO2 hit and i was amazed when he sucked down his bailout tank and then much of mine in a very few minuets. I do believe however that this hit was not undeserved.

I used my rig with a DSV initially, ran a BOV for about 100 hrs, and have gone back to the DSV.

I clip off my BO second stage to a loop of bungie around my neck, and check it every dive. I am carefull to only have a breathable gas to hand around my neck.

My reasoning is simply that on balance my rig is very simple to operate in much the same manner no matter what or how committing the dive. I played with various plug and play set ups with the BOV but found the process much more demanding in practice than in theory.

My unit is less fussy and easier to maintain with out the BOV. It is more comfortable while scootering. I swear it breaths better.... I have no reason to milk the last bit of time from my sorb, and don't.

I have had a good time playing with various set ups on my rig. The stand, BOV, and various sliders and QC6 fitting were a good for learning that for me simpler is better. To me it seems that many in this community choose complex solutions over more robust simple ones.

While we may refer to this activity as technical diving, I tend to think of it as much as a craft skill. Simple repeatable procedures, good hygiene and frequent practice make for a good and safe diver. Much as I like my gizmos.

A rock may fall upon me or, more likely, I may make a mistake. For me the balance of probabilities suggests that a CO2 hit is much less likely than a great faff on the surface or having serious difficulty pluging or unplugging a connector while otherwise engaged.

I have found that on longer dives I find it very difficult to be arssed to do the simplest thing. It takes a great deal of will power to switch out anything while freezing on deco. I am now of the opinion that the begging and the end of the dive are the times when I am most vulnerable and I need to pay the most attention.

Peter
 
I have no real way of knowing how ill react to a C02 hit as I have never had one on CCR. (I think I did on OC)

I have heard enough tails of people not being able to swap regs for me to conclude the minor hassle of running a BOV is worth it


I would much rather I had a C02 hit and discover i didnt need the BOV after all, than not have one and die knowing I did.

Thats basicly what it comes down to for me

ATB

Mark
 
PeterN said:
I clip off my BO second stage to a loop of bungie around my neck, and check it every dive. I am careful to only have a breathable gas to hand around my neck.
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I'm curious how you manage to always have a breathable gas hanging around your neck on a dive that requires hypoxic gas. For example, a dive with 10/60 bailout for bottom gas. Is that hanging around your neck when you first enter? It is not safe to breathe near the surface if a problem develops. Or do you instead hang your 50% deco bottle on the necklace, which is no good at depth? Or do you switch necklaces as you descend? That is certainly a "simple" system.

There is no easy answer. We all weigh the risks and make configuration changes based on what we think will work best for us. The probability that a problem will develop while shallow may not be any different than the probability of a problem at depth. I already know of at least 2 cases. One was a fatality without a BOV. The other was Mark, who could have been a fatality because of the BOV. The only fail-safe system is the one where you leave the rebreather at home and go to the pub instead.
 
kwinter said:
I'm curious how you manage to always have a breathable gas hanging around your neck on a dive that requires hypoxic gas. For example, a dive with 10/60 bailout for bottom gas. Is that hanging around your neck when you first enter? It is not safe to breathe near the surface if a problem develops. Or do you instead hang your 50% deco bottle on the necklace, which is no good at depth? Or do you switch necklaces as you descend? That is certainly a "simple" system.

There is no easy answer. We all weigh the risks and make configuration changes based on what we think will work best for us. The probability that a problem will develop while shallow may not be any different than the probability of a problem at depth. I already know of at least 2 cases. One was a fatality without a BOV. The other was Mark, who could have been a fatality because of the BOV. The only fail-safe system is the one where you leave the rebreather at home and go to the pub instead.
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I clip my rich Bo initially, then swap it out for the lean mix.

I agree ther is no easy answer. Also it is easy to forget that conditions are so very different for all of us.

I reserve the right to once again change my mind about any of my gear configurations. My rig now is as it was when I got it from the maker. It seems I had to try almost everything before appreciating just how well the set up worked out of the box.

Peter
 
The day we stop arguing the rationale for accepting or rejecting configurations, procedures or equipment will be a dark day indeed.

As always the important/interesting thing is not what you think but how you think. Nobody has tried to argue based on aesthetics. ;0)
 
silentbob said:
The day we stop arguing the rationale for accepting or rejecting configurations, procedures or equipment will be a dark day indeed.

As always the important/interesting thing is not what you think but how you think. Nobody has tried to argue based on aesthetics. ;0)
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Probably one of the best posts I've read in quite some time.
 
Mark Chase said:
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
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Agree!

Igor P

Sent from my PAP4500DUO using Tapatalk 2
 
Without trying to cause a massive directional change in the thread can i introduce the discussion of gag straps (mouth piece retention straps). The unit in discussion originally is know for coming standard with this. The discussion of positives and negatives does quite relate to the use of a BOV. Recent investigations have shown the large number of fatalities that can and have been avoided by the use of a gag strap yet people who avidly promote BOV usage choose not to use another very simple system that makes the system safer (provided you train your skills).
I have had this discussion along with the base concept that with in technical diving people are regularly trying to become "safer" through the use of technology rather than training. Base level skills and practising them should be the foundation of your diving regardless of what your configuration is so you can deal with the problem when it happens.

For the note, to be quite open, I dive my rEvo without a BOV but with the gag strap as bailing at the depth I regularly dive onto a BOV would result in an empty DIL tank quite quickly and without modifying my unit with loads of extra failure points that is not an option. I will point out though that I am aware of what I am doing (as in what I have to do in the event of something going wrong) and make sure my skills are fresh.
 
Edd said:
bailing at the depth I regularly dive onto a BOV would result in an empty DIL tank quite quickly and without modifying my unit with loads of extra failure points that is not an option.
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This is true only if you have the BOV connected to your onboard dil tank. Please do not confuse plumbing issues with the pros and cons of using a BOV that were being discussed. There are numerous ways of dealing with that issue, but that would certainly be a "massive directional change in the thread."
 
As the OP for this thread it appears the bottom line is rEvo do not have a BOV ready to go. Thanks for all the contributions.
 
cathal said:
As the OP for this thread it appears the bottom line is rEvo do not have a BOV ready to go. Thanks for all the contributions.
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I got a golem shrimp of The shelf, fitted on the original rEvo hoses. Don't know how much more you want it ready to go ;)


Sent by my rEvo scrubber using a shearwater Nerd
 
Love a good discussion guys

BOV or not is personal choice (reasons for both)
BOV with inboard or offboard connection is also personal choice (reasons for both)

Use of gag strap should be no brainer and is highly recommended in my book, especially when using BOV as it removes any issues with weight on mouth
 
Just to note that Revo now have their own BOV. Not listed in spares, but listed in the price list:

R610; 48600890; BOV including spiders, valves, MP hose, connections to breathing hose €500
R611; 48600870; clip for HUD/NERD on BOV €16
R612; 48620612; conn. set for rEvo breathing BOV hoses to rEvo III housing: insert (2X)+screw (2X)+ SS hose clamp (2X) €80

All plus delivery and tax (21% in Europe)
 
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