To BOV or not BOV - Split From NACD Cave Summit

Drmike

One thing that could be beneficial, using a BOV with the nova FFM or any FFM could make assisting a unresponsive diver (say someone who is toxing) a lot easier - buddy can turn the BOV to OC

__________________
Get a girlfriend you sad twat - a Rebreather is an unfaithful mistress - dont blind yourself to her faults just because she goes down on you

Peter Piemonte

Agree with Drmike, Dave Sutton and others who have promoted the use of a BOV. I bailed out to OC once on a non BOV equipped rig, due to a caustic cocktail. twice on a BOV equipped rig due to mild CO2 hits.

As Decodiver and Scubadadmiami point out, you don't have much choice with a cocktail, but in all other scenarios, the BOV is a very easy way to get off the loop and provides a smooth transition to OC bailout. Even without experiencing a full blown hypercapnia event, it is very difficult to control yourself sufficiently to make the exchange. Perhaps if I were more diligent in practicing that skill, it would be different. The use of heavy gloves and cold water complicates things furthur...

I prefer the added redundancy and ease of transition of the BOV, and would be reluctant to dive without one.

With the CEJN quick connect, I can plug in any of my bailout gas to the BOV or use the second stages on my bailouts.

Regards, Peter

diverreb

Reading about others experience with Hypercapnia I would think it's a good idea to be connected to the BOV through offboard gas either directly or through a switch block. If I were fighting for gas & was to the point of not being able to get off my BOV to the bailout reg, as some have described the condition, I surely wouldn't want to have to pop a quick connect, and hook it up to another hose, especially in cold water with heavy gloves on and in somewhat of a state of mental stress.

A lot of this is dependent on your depth & how much Dil you have to feed the BOV. I really have no idea how long it takes to get Hypercapnia under control, that is your breathing rate back to a normal level once the switch to OC is made.

For all other instances, if you have time to make the QC changeover, you probably have time to switch to a Bailout reg, if you so choose.

I went through this exercise when I was thinking about changing all my fittings on the rig, drysuit, and BC to QC fittings so they would all be the same and interchangeable. Turned out to be a very expensive proposition to avoid an extra hose on a Bailout bottle with a fitting that matches the QC on my BOV.

Richie

Janos

I have a BOV connected to the inboard of my Classic Kiss.

My thinking is that I like rebreathers to rebreathe, and bailout to be seperate, so bailout only has a reg connected to it - fewer things to go wrong. And it can be handed off if needs be.

The reason I have a BOV is that it makes it easier for me to get on my off-board. Yes I can hold my breathe, spit the loop, and fumble for an OC reg. But it's far easier for me to do this with a working reg in my mouth. Especially if I go hypercapnic.

Janos

__________________
You can lead a horse to water but you can't climb a ladder with a large bell in both hands - Vic Reeves
www.hellfins.com/shed

rhelsley

The thought that comes to my mind as a suitable compromise between an easy bailout and considering the cocktail issue is having the bailout regulator around the neck on a bungee necklace.

I had an issue a year ago with a severe retained CO2 hit, resulting from a snowballing series of events on a dive to 230'. My rebreather kevorkian was designed around 40cf dil & o2 tanks, and my primary bailout is plumbed from my dil tank, the regulator mouthpiece held under my chin with bungee with a hose long enough to pass off to a buddy if kept close.

When I began to realize there was a problem (serious uneasiness, burning throat, vertigo, increased heartbeat & breathing) it was an easy switch over to diluent bailout. I switched over by pulling the dsv from my mouth and placing the bailout reg in, without fumbling with the dsv shut off, to secure a good breathing source and then afterward closed the dsv and purged the loop to force any water ingress out the bottom CL mounted OPV. I had sufficient gas volume in my diluent cylinder to compose myself and then later switch over to my 80cf bailout for ascent. Also my 40cf O2 tank was fitted with a mouthpiece for bailout scenarios such as this, kept on a short hose and with a shut-off valve, and clipped to my right hip d-ring to prevent accidental deployment.

Except for extreme dives requiring multiple gases for OC bailout, using a long hose on the slung bailout tank around the neck, and mouthpiece hung under the chin could be a better configuration than keeping the regulator mouthpiece bungeed to the bailout tank neck, which is far too distant and difficult to deploy in a bailout situation such as I experienced. It may make offering that bailout to another diver more complicated, but at least for your immediate bailout needs, whether CO2 or cocktail related, it is an easy switch over.

These design considerations, tested unforseen on my self, were definitely a factor in surviving my CO2 incident. I've seriously considered integrating a FFM with BOV or simple BOV into my system, but for simplicity's sake I haven't come up with anything more elegant than what I currently use, but I haven't given up just yet.

regards,

russell

UKSteve

Any thoughts on the relative merits of the Golum type BOV (twist knob to operate) vs the forthcoming APD system (roll barrel to operate)?

- WOB?
- Speed to operate?
- divability?

I do not have a BOV (yet!!) ... was waiting to see the APD one first. It seems to me that the twisting knob might just be a bit easier and intuative (to both owner and buddy) when the cr4p starts to hit the fan. Still sitting on the fence gathering splinters here.

Steve

Mark Chase

Golum /V4Tec and Divematics can all be operated single handed. The KISS one should as well by my one was quite stiff. The AP unit APPEARED to be a two handed function. However i thought it was an interesting design and it also appeared very light and compact.


Any of the Golum V4tec or Divematics group are good. Back up and service from Golum has been excelent so id recomend them.

ATB

Mark

__________________
Is it supposed to make that noise ?

I took my unit to the dive shop and demanded they bolt on every thing that would fit.

Join my elite diving teem and get a Tshirt

"Doing It Chasey"Hammerhead Eccr Advanced Diving System

lizardland

It needs stripped, cleaned and re-greased. Mine was like that, twisting it almost pulled it from your mouth but re-lubing the whole assembly fixed it. It should work very smoothly.

__________________
Can you imagine drifting along in the sea with your mouth open and a load of f***ing plankton going in? You'd like it, would you?

www.westons-cider.co.uk

Azerbaijani Association of Technical Divers Publicity Officer and Goat Wrangler

Dave Sutton

Here's the fallacy: NO YOU CAN'T. Not in any sort of real C02 hit. ESPECIALLY not deep.

By the time you can even think that you need to do it, you cannot hold your breath for 2 seconds. You'll drown. To think otherwise is wishful thinking. I used to believe that what you write was true. My experience proved otherwise. I'm wiser now...


Dave

__________________
.

"All animals are equal, but some animals are more equal than others"


Professional Small Boy: Never Successfully Cubicled.

Mdemon

Ditto. I know someone who has taken two hits - one with, one without BOV. In both cases, breath-holding was impossible and the BOV made the switch easier (although the event was no more pleasant).

Why take the risk? No downsides other than cost. Stuff the Luddites, get one. Any Luddites might want to try a hit or watch someone having one before nay-saying.

__________________
www.southwestmafia.com

It's as easy as abc;

a) "Carry adequate bailout"

b) "If in doubt, bail out"

c) "Always know your PO2"

If you find that hard, stick to crochet.

"Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"