BOV with MAV and/or ADV - thoughts?

[JohnnyC]

Ultimately, it's not rocket surgery. Plumb in offboard through a QC6 to your BOV and drive on. Short-ish hose on the bottle, long-ish hose on the BOV (QC'd just to make everyone squirm a bit)

Check your gas where appropriate, whether it's on a boat or at 6m when you drop your O2 bottle.

Plumb your BOV offboard unless it makes sense not to (LP50's as backgas bailout). Plumb your BOV oonboard unless it makes sense not to (3L onboard and a dive deeper than say anything where you can't stand up with your head out of water....)

Switchblocks will get you killed. One QC6 on a hose is fine. Plug it on the surface, switch it underwater. If you can't accomplish this you shouldn't be diving a rebreather. If you can't hold your breath for the 2 seconds it takes to plug in a different offboard gas in the event of an emergency, you done screwed up boy. And who dives bailout that doesn't cover an acceptable range of depths anyway? Nobody goes from tox to hypoxic. Figure it out, you've got time.....

BOV's are great. BOV's also suck. It's a personal choice, I like them, others don't. Aside from having larger genetalia than everyone else in this thread, there's not much difference. Seriously, ask your wife/gf/significant other.

 

[PfcAJ]

Rb80 BOV is hard plumbed to the bottom gas bailout. Sometimes that’s like 10/85.

I just accept that for the shallowest 20ft of the dive I can’t switch to that for any length of time and get on with my life. The extreme majority of the dive is spent outside of that range.

 

[joshk]

Rb80 BOV is hard plumbed to the bottom gas bailout. Sometimes that’s like 10/85.

Strange, I would have expected it to be plumbed into whatever drive gas is.

 

[PfcAJ]

Strange, I would have expected it to be plumbed into whatever drive gas is.

Common misconception. It goes straight to the right post on the backgas. No QDs or nuthin.

 

[hroark2112]

When I learned to dive CCR I learned on a Kiss with a BOV. After a while I got an O2ptima with a DSV. I was nervous to say the least. Once I got used to the DSV and a necklace bailout reg I was fine. Bailing out was really easy and the necklace reg saved my ass once big time, to the point where even diving BOV I use a necklace bailout.

Now I upgraded the O2ptima to the backmount CL setup and iBOV I’ve had to learn to dive that system. I like the iBOV but the handle issue sucks. Before every dive I cycle it through and loosen it up. Also the ADV isn’t all that great. It’s loud and horrible sounding. I don’t use it except if we’re divebombing a wreck and trying to get down really fast.

The gas hoses strap to the loop and really are not in the way at all. In photos it looks like it would be a huge issue but it really isn’t.

When I’m diving my own bottles I’m diving steel LP 27’s filled to 3000ish. If my BOV is plumbed into them, I have lots of gas. I’ve only once done vacation diving with the new setup, but this thread has me thinking of utilizing the off-board whip for my BOV. Usually I seem to find AL20’s on vacation, so plugging in to the off-board seems like a good idea.

All good stuff to think about here in this thread. Thanks guys!!

 

[stuartv]

@hroark2112 Thanks for posting your own real world experience. Does your iBov have the optional bigger handle thing I read about here and saw on their web page? Just wondering how much difference that makes to ease of turning it.

Also, how do you feel about using the MAV levers on the BOV versus past experience with a MAV on your chest (I presume)? Does your DR still have a MAV on the chest also, or is it just the BOV/MAV?

 

[hroark2112]

I don’t have the bigger handle. I hear it is a noticeable difference though.

No MAV on the chest. For me it took a few dives to quit reaching for it. I’m sure had I learned initially on it that would not be an issue. Muscle memory is a good thing, and retraining the hands took a few dives.

It is easy to use the levers on the BOV. Since I dive with the ADV off most of the time, it’s easy to clear the ears then add some dil, my hand is in the same place.

 

[rddvet]

@hroark2112 Thanks for posting your own real world experience. Does your iBov have the optional bigger handle thing I read about here and saw on their web page? Just wondering how much difference that makes to ease of turning it.

When I walked into their office I got to try one with and without the lever addition. Of course it was on dry land and wasn't in my mouth, but there was a significant difference.

 

[rddvet]

Can anyone post a photo of a QC6 inflator cheater that I've heard about. I'll be inflating from one onboard tank and was told about the QC6 cheater in case that reg fails or bottle goes dry(though it shouldn't). I've heard some people just add an inflation hose to bailout bottles, but why have extra hoses that will rarely get used. I assume the cheater is just a female QC6 on one end of an inflator hose. Should be small enough to keep in a drysuit pocket I suspect.

 

[tbone1004]

Can anyone post a photo of a QC6 inflator cheater that I've heard about. I'll be inflating from one onboard tank and was told about the QC6 cheater in case that reg fails or bottle goes dry(though it shouldn't). I've heard some people just add an inflation hose to bailout bottles, but why have extra hoses that will rarely get used. I assume the cheater is just a female QC6 on one end of an inflator hose. Should be small enough to keep in a drysuit pocket I suspect.

what are you trying to sort out and how are your bottles rigged now?

Couple schools of thought.

1. You can put QC's on each of your second stages and if you want to plug in that bottle to the rebreather, you pop the second stage off, plug in, and put second stage in pocket or clip off to your rig. Downside to that with QC6's is they're rather big/heavy so that may be a problem if you need to breathe off of them *i.e. caustic gets into the bov and you can't breathe off of it*. It's also really expensive as you need a full set of QC's. My price from them, set up as a commercial account, is $45 for each side and that's not including the machining and/or adapters to take them from NPT to something a bit more useful for diving. That's about the only way you can do it if you only want one hose on each of the bailouts, but at $100 per reg, it may not be something you want to justify.

If you are OK with a second hose, you can choose one of two options.
2. BC inflator hose-if you go this route, the "cheater" is from a BC nipple to male QC6. You can't use this to feed the BOV though as the flow rate isn't high enough *otherwise we'd use bci's....*. Advantage to this it's the cheapest option since you only need the one extra male QC6 and can either make a rigid adapter with a mnpt BCI or put a short hose in the middle of it.
3. Reg hose- if you need to breathe off of the BOV, this is much better. The reg hoses are all terminated in male QC6's and you can choose to keep an extra female QC6 to female BC QD adapter in your pocket, again hard connect or with a hose.

This is a QC6 female to BC inflator male, so would be option 3 above. Change the two female connections to the male connections and you have option 2.

If you want to go with option 1, there are much less expensive and much smaller QC's out there with many of the most economical shown below. If you want to stay with one hose on your bottles, I'd put these on all of your second stages. For these, the female goes on the hose, male on the second stage since they are SESO instead of DESO. In this case, if you are diving with teams that use QC6's, you will want to make two adapters to be a good buddy. One that is m2m QC6 and whatever QC you choose and give to your buddy to be able to use your bottles. The other is for you and should be f2f of QC6 and your QC so you can use his.
Quick Disconnect Adapters Piranha Dive Shop |
Not as ideal as utilizing the same QC's as your buddies/teammates, but it's an option. While I don't think QC6's are necessary, cave country seems to have standardized on them in the last few years so I just bit the bullet and went to QC6's.