First Rebreather Questions

[rjack321]

Longhose under the loop with an elbow on the reg, the mouthpiece inserted into a rubber necklace. The excess hose is looped under bungees on the bailout cylinder on the LHS.

The main use is for my safety when the rebreather fails. It is very simple—and practiced on every dive—to exchange the loop and breathe from the necklaced regulator.

A very secondary use is to donate to another OOG diver. This is two phases: I grab the regulator, pull it from the necklace, and thrust it towards the OOG diver whilst pulling the stowed hose from the bailout bungees with the other hand. Once stabilised, remove loop and lift hose over my head (possibly wearing a helmet), then back on the loop.

Not using a gag strap? why not?

 

[Wibble]

Not using a gag strap? why not?

PITA with a helmet. Happy not using one for normal diving.

Do have a gag strap (Revo), but have removed it for convenience.

 

[rddvet]

BOV and necklace? Really why?

Having more crap hanging around isnt really that useful vs having one reliable response to gas problems

I don't find it annoying at all to be honest. I don't even notice it. It also doesn't negatively effect my decision making with a gas problem (at least when practiced since i"ve been lucky enough to be fairly problem free). My first instinct is always bov. When my wife has pulled an OOA on me for practice, I don't accidentally grab the necklaced reg instead of the long hose. It's also super easy to go to the necklaced reg if need be due to something like a caustic (which again I've only practiced on the fathom, not expereinced). And other than a CO hit, most CCR issues don't just sneak up on you, so you're generally not making a snap decision on what reg to go to. So my thought process is it's not an annoyance, it doesn't hinder my emergency decision making, but I end up with a tertiary gas option in case some weird unheard of (aka never going to happen) problem actually arises. And like Ken, early in my ccr days I was futzing with stuff and accidentally unseated my QC6. I didn't have to go to bailout or anything. I noticed it when I added dil and fixed it. But it also made me think if I actually had an emergency in that scenario would I be fast enough unclipping the long hose and getting a breath? Probably, but a necklaced reg is faster and I have actually practiced it to gain muscle memory.
I'm not being argumentative just to be clear. I think your points are valid, but for me there's no negative.

I'm one of those guys that does that, I don't find it that busy. The BOV on my fathom is driven by a QC6 connected to whatever my DIL/Bailout bottle is at the time. I've had an experience where the QC6 popped and I needed to add loop gas to catch a breath, it was unpleasant to say the least.

Oh yeah, and this kook is one of the people who taught me some stuff about using ccr in caves.

 

[Underwater Tourist]

In MX, I noticed that most people dive without bov.

Is it just a local trend or is there anything particular about diving MX styles caves that would favour dsv+necklace reg?

 

[broncobowsher]

That made me think of what my local BOV scene is like. Mostly rEvo, Choptima, Prism, and a couple Posidons. The Posidons have a BOV, just how they are all built. I think there is a Prism with a BOV, will have to double check next time I run into him. The rest, DSV.

 

[rddvet]

In MX, I noticed that most people dive without bov.

Is it just a local trend or is there anything particular about diving MX styles caves that would favour dsv+necklace reg?

I could be wrong, but I bet you're mostly seeing sidewinder divers. If thats the case, its not the easiest unit to setup a bov with. Though nowadays its been pretty much figured out. But besides that a lot (i would say the majoroity) of sw instructors don't prescribe to the importance of a bov and therefore dont recommend them to students. But alot of sw instructors don't see the importance of a hud eventhough a sidewinder diver died unnecessarily because he didn't have a hud warning him. I personally wouldnt dive without either

 

[jale]

a sidewinder diver died unnecessarily because he didn't have a hud warning him. I personally wouldnt dive without either

Hi
I think this kind of statement is wrong as it gives the impression that a hud is THE primary piece of kit.

The inflation in new equipment, the ease to access to these pieces pieces of equipment is all good even if sometimes I see it more as a market for "middle-aged-guy-having-a-middle-life-crisis stuff" in the same vein as buying the "dream-car" or going to instagram yourself on top of mount Everest.

But many people are forgetting the basic which is "know your ppo2" and no one should not have a device to remind you about that.

Rant over

(I don't dive a Sidewinder!)

 

[Underwater Tourist]

I could be wrong, but I bet you're mostly seeing sidewinder divers. If thats the case, its not the easiest unit to setup a bov with. Though nowadays its been pretty much figured out. But besides that a lot (i would say the majoroity) of sw instructors don't prescribe to the importance of a bov and therefore dont recommend them to students. But alot of sw instructors don't see the importance of a hud eventhough a sidewinder diver died unnecessarily because he didn't have a hud warning him. I personally wouldnt dive without either

Yeah its 90% SW divers

Are you referring to the SW guy who died in FL with the O2 shuttoff in the off position?

As for HUDs, with all the reading and asking around I have done, it really seems like it must be a mandatory piece of gear when you start learning ccr. And then maybe down the road you decide to remove it

While dsv vs bov debate is more nuanced and really comes down to the student's preference and instructor influence

 

[broncobowsher]

The lack of O2 has no symptoms. You are doing fine, everything is great, you are passed out and unconscious. No feeling that things are off, nothing that says there is a problem coming. It's just lights out.

I'm surprised to find that some form of HUD isn't standard on every rebreather.

A few years back there was a rebreather diver who died in a swimming pool. lack of oxygen, not good.

 

[DiveLikeAMuppet]

Yeah its 90% SW divers

Are you referring to the SW guy who died in FL with the O2 shuttoff in the off position?

As for HUDs, with all the reading and asking around I have done, it really seems like it must be a mandatory piece of gear when you start learning ccr. And then maybe down the road you decide to remove it

While dsv vs bov debate is more nuanced and really comes down to the student's preference and instructor influence

Technically you don’t “need” a HUD, you should be warned by dropping loop volume that you consumed too much of O2. Works really well as long as you don’t change depth or don’t get stressed or don’t use an ADV or …

There are some pretty famous cave instructors who preach things like “you need to recognise your REMs completely blind” who dive without a HUD which feels like a red flag. I think a HUD would keep you alive while task loaded or in really bad viability. Counting blips is easier than pressing a computer against your mask and your brain will get alerted when they go from green to orange / red.