BOV Use Poll

gottrimix

You haven't even done your class yet and you already have the BOV option figured out huh

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Steve

www.lakemeadtechnicaldivers.com

grahamsp

Sadly, it's not that simple. Hypercapnia degrades the diver's ability to perform mechanical tasks, even simple ones, and going off the loop onto OC bailout is not simple. If you think it is, try doing it at depth under stress. It can be a sphincter-clenching business.

You should also consider this. Because going to OC bailout is not simple, the consensus view seems to be that divers experiencing the early onset of hypercapnia delay getting off the loop as they try to solve the problem by deep breathing, flushing, reducing workload etc. Often that does work. But sometime it does not, and in that case, getting off the loop can be just too difficult. The brain knows what has to be done, but the body just cannot do it. That's what hypercapnia does, and to great extent why it's a killer. At that point, you are stuffed unless you have a buddy to hand who spots what's going on, and lends a hand.

In contrast, precisely because going off the loop using a BOV is such a simple, one-handed exercise, divers tend to do it sooner rather than later, before hypercapnia reaches dangerous levels. That's certainly been my experience in the three situations where I've had to bale out in earnest.

We all trust our loops, otherwise we would all be still diving OC. What you are arguing for is an absolute, blind faith that the loop will never, ever let you down. Well, it can, however well packed a scrubbed you have. It is possible to work so hard that there is simply too much carbon dioxide being pumped into the loop for the scrubber to cope, at which point bailing out is the right thing to do.

I have never been troubled by the weight of my Kiss BOV. If the loop is the correct length, the problem of jaw fatigue is largely eliminated. And I did not notice any increase in WOB when I went to a BOV.

Of course there shouldn't be a reason to use a BOV, but sadly, in the real world there are. Shit happens, as they say, and to dive assuming that nothing will ever go wrong is just asking for it. The worst dive of my life was caused by a current-assisted close encounter at 67 metres with a mono-filament net the size of a barn that appeared out of nowhere, a dive I survived because, even while I was working my tits off to get clear, I was able to go to OC the instant I felt the onset of hypercapnia.

No argument, but I think there's more to the BOV issue than you realise.

Rgds,

Graham

PhilSiswick

Personally, based on the experiences of many others on here (including some posted in response to your post), I decided that a BOV was a must have even for the relatively lightweight diving I do (and will do for quite a while) on my unit.

In my experience now, there are are few downsides to a BOV (more failure points and cost) and only one failure mode where it can't be used to give you sanity breaths (caustic cocktail). It will certainly ease your transition to full OC bailout (for which it is, for me, not a substitute). Plumbed in offboard, it's even a substitute for dil manual add or ADV.

I fail to see why anyone would turn their back on something that adds so much security and safety at so little cost. For me, doing without would be like voting to have the ABS switched off on my car.

YMMV, but I'd seriously urge you to read up on people's experiences and review your decision in the light of that.

Cheers,

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Phil (WSKD 0001)

I have always felt that the dive I am on is not nearly important as the dives I plan to be on the rest of my life. Tom Rose, 2007

The person who gets the farthest is generally the one who is willing to do and dare. The sure thing boat never gets far from shore. Charles A. Lindbergh

www.hugsac.org.uk

nigelh

My God. I wish.

I don't like the BOV.
It's clunky. It's got hoses that add to the clutter. It's something else to test and maintain.

However the one time I needed it and I didn't have it I was trapped on the loop with brain-stem instincts insisting I could not, would not, pause my desperate breathing while my brain screamed "It's CO2! Put the damn bail out in your mouth!"

The second time I needed it I had it so turn the knob, signal <problem><up> to my buddy and call the dive.

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nigelh

decoweenie

Don't you remember that from 0 to 50 hours, the diver knows it all and is an expert... :wink:

decoweenie

I guess the same argument could be made about OC-bail-out like most alpinists do. Will you be one ?

caveseeker7

Phi, the point is that he won't need OC bailout, hence he won't need a BOV.
Cute in way, isn't it?

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Cheers
Stefan



"Political Correctness is a doctrine, fostered by a delusional, illogical minority,
and rabidly promoted by an unscrupulous mainstream media,
which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"

Gilles

Have you ever used one

Have you ever used one on a long dive

More . Clearly you have never even tried one, let alone experience any kind of extended range dive with one

Best to think a little bit more.

As a BOV user, I agree with every argument presented for them.

The only valid argument against is that it is extra kit and complication, easily justified by the added value of increased safety. The only possible substitute is FFM.

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Gilles
http://www.dirrebreather.com

Dsix36

I am really getting alot of info from this thread.

I do not currently have a BOV, but am leaning towards it very heavy. I know for a fact that with my Rebreather diving, I am hesitant to come off the loop and go to OC. I want to "fix" the problemand remain on the loop. If the BOV were there and merely a twist of the knob was all that was necessary, then I would not be hesitant to do it. Dealing with putting the bailout reg back is a pain and I don't want to do it if I don't have to.

I stiil do bailout drills, but at my convenience so I can deal with the reg and hose.

CO2 is the only thing about Rebreather's that really scare the s**t out of me. I am very conscienscious of my breathing pattern and always ready to bail if my breathing rate goes up for an unknown reason.

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THE MORE THAT I LEARN, THE MORE THAT I STILL NEED TO LEARN!!!!!!

Solitude Diver

I'm getting a lot from this thread too. Thanks to all of the posters. It helps to hear from others who have actually had to deal with emergencies.

So, going from "might consider a BOV in the future" to "most likely will soon", I cannot seem to get an answer as to how to get the APD BOV for the Evolution.

Can anyone tell me where you can order one?