Status of Left Lean and Right Rich Philosophy in B/M Open Circuit Technical Diving

[ND5342]

As the question to the validity of this philosophy came up in another thread. I have decided to run a poll to see the current status of use of this type of gear configuration.

Remember this is Backmounted Technical Open Circuit Diving.

 

[UCFKnightDiver]

I voted "was recently taught that way" as it's something we discussed in my AN/DP class but also it was stressed to ALWAYS verify bottle contents when doing gas switches and to engage in the proper procedure for this. I was in sidemount and we were able to experiment with multiple ways to carry several additional bottles including balancing them out on both sides and carrying everything on the left side. I wrap the long hose similar to how people do it in backmount, so if I do carry a bottle on the right side, I have to be extra careful to not trap the long hose or switch to bungeeing the long hose to my right side sidemount tank.

 

[Searcaigh]

I wasn't taught that way so didn't vote, you need to add another option.

 

[ND5342]

I voted "was recently taught that way" as it's something we discussed in my AN/DP class but also it was stressed to ALWAYS verify bottle contents when doing gas switches and to engage in the proper procedure for this. I was in sidemount and we were able to experiment with multiple ways to carry several additional bottles including balancing them out on both sides and carrying everything on the left side. I wrap the long hose similar to how people do it in backmount, so if I do carry a bottle on the right side, I have to be extra careful to not trap the long hose or switch to bungeeing the long hose to my right side sidemount tank.

Thanks for sharing. I should have thought about sidemount. I am really looking answers to those diving back mounted cylinders. I rephrased the question.

 

[ND5342]

I wasn't taught that way so didn't vote, you need to add another option.

What way were you taught?

 

[mc42]

PADI Tec materials describe LLRR as a common configuration if you do wear bottles on the right. I don’t wear any bottles on the right, nor was I taught to do so.

 

[Wibble]

Whilst it might work out that way with lean bailout on the left and rich deco gasses on the right, I would never ever not check the cylinders before breathing from them.

The problem, IMHO, with all of these prescriptions is they lead to problems. For example on a deeper OC twinset dive, I'll have 3 ali80s which will be the 50%, 80% and a bottom stage with backgas. Once down, I'll switch to the bottom stage - checking which gas it is first. Use it until mostly consumed, then switch to back gas. I keep that on the RHS as I find it easier. When getting to the first deco stop I'll switch to the 50% on the LHS, but check it first, even if I know it's the only cylinder on the LHS. Same with switching to the 80% (I don't like 100%, too hot) on the RHS.

If, when diving with two stages on the RHS, I need to do a donate then it'll be from my mouth and close in to the other diver - there's plenty of hose for them to breathe; I'll scoop up my backup. When settled, then I'll unclip or faff with the other stages to free the longhose all the way. It really isn't difficult.

Obviously if it's the rebreather it'll be a donate of the bailout reg. If the crap's really hit and I need to donate at deco, it'll be the reg in my mouth and I'll go back on to bailout.

BTW I sidemount bungee the bailout and deco stages back to keep them under control during the bottom phase.

Everyone's different. Let's enjoy that.

 

[tbone1004]

I voted "Heck no" since it is specified that we are in backmount, open circuit. The gray area is that outside of that configuration I do split my bottles up.

 

[jlcnuke]

For AN/DP I was taught to put the deco bottle(s) on the left, I don't remember if the materials discussed it at all.

The TDI Trimix course teaches lean left/rich right as a good option and, other than mentioning that you should be careful to not trap your long hose, it mentions benefits over putting all bottles on the left but no cons (definitely seems to promote that technique for attaching bottles in my opinion). I've only done the e-learning so far, but from my conversations I believe the standard method my instructor teaches is to put all on the left.

 

[MichaelMc]

I have no knowledge of the subject, but was currious of the results. So I voted ....

Wow those results look random/interesting/expected.

I'm a fan of the option "I have no idea but wanted to vote anyway" to cut down on the noise in surveys.

(I didn't vote, as I don't know.)