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

[ND5342]

Deco stages to the left, right hand side is clean (IANTD)

Then that would be choice number one "Heck no, I don't prescribe to that antiquated, inappropriate system."

 

[ND5342]

Would be nice if you changed the poll to allow viewing results without voting for those of us who must abstain. Otherwise you're getting at lest some pencil whipped answers.

I hope not. I want people to vote however I will allow viewing after a week or so.

 

[Wibble]

What benefits does it list? Just curious.

For the benefit of people not familiar with deco diving and long hoses....

All Stages Left is DIR (Doing It Right - yuck) / Hogarthian (after its inventor) where the right hand side is kept clear so you can immediately deploy the 2.1m/7' longhose: simply grab one's second stage at the swivel with right hand, out of mouth, over head, thrust into the face of the donee. Scoop up backup on bungee under your chin and breathe, move to unhook the longhose from beneath the torch battery.

No stages in the way to catch the longhose. If you need a third stage, you use a leash and effectively tow it along between your legs with it clipped off on the left-hand waist D-ring. The cylinders aren't in a specific order so DIR practitioners will practice "stage rotation" drills to move them around on the left-hand-side. DIR puts great emphasis on ensuring that you cannot breathe the wrong gas at depth, almost encouraging team-mates to knock the regulator out of someone's mouth if it's the wrong one. DIR keeps the decompression stages turned off (but pressurised) in the water.

N.B. a full DIR harness does not have a D-ring on the right-hand waist.



Lean Left Rich Right is an older method (I believe) which uses both sides and orders the cylinders to have the leanest on the left and the richest on the right. This makes it easier to determine the order of breathing them. Arguably it could encourage bad practices where the cylinder's used on trust without verifying the gasses.



Rebreather divers frequently use both sides as it balances the diver. Mostly rebreather divers will be taught to keep the bailout (the gas breathable on the bottom) on the left hand side and turned on ready to breathe. This naturally leads to the decompression bailout gas being held on the right-hand side. As there's no longhose (**GUE JJ rig excepted), there's no need to be precious over mounting cylinders on the right-hand side, thus they'll tend to do LLRR.

Rebreather gas donation to an out-of-gas diver comes straight from the bailout cylinder which is always turned on during the dive. The rebreather diver will be well practised at deploying that hose as they should practice this on every dive when they get to the bottom (or 5m/15') to validate the bailout is working before they need it.



** GUE have their own 'customised' version of the JJ rebreather which has been modified to emulate a DIR rig, so has a longhose bungeed backup, all stage and bailout cylinders left, etc. Will leave that to a GUE proponent to explain.

 

[shurite7]

There should have been the option, learned about both, but use one method based off of research and experience, or learned about one and switched after learning about the other. Back when I took tech, my instructor went over both methods. We had discussions about it and dive with both methods.

Due to the lack of options, I didn’t vote. I learned both, yet the preference was left-lean, right-rich. I do prefer bottles on the left, but do not consider left-lean, right-rich antiquated or inappropriate. It is personal preference or team determined.

 

[ND5342]

There should have been the option, learned about both, but use one method based off of research and experience, or learned about one and switched after learning about the other. Back when I took tech, my instructor went over both methods. We had discussions about it and dive with both methods.

Due to the lack of options, I didn’t vote. I learned both, yet the preference was left-lean, right-rich. I do prefer bottles on the left, but do not consider left-lean, right-rich antiquated or inappropriate. It is personal preference or team determined.

I am looking for peoples' current view on the subject so that is why I did not have the choice of "what you learned on". Are you currently diving using both methods or what the "team decides"? I could make that a choice if it is that popular. Again remember this BM Doubles.

 

[PfcAJ]

I absolutely do not.

Bottle position is not an indicator of what’s actually in the tank.

 

[stuartv]

My original AN/DP training was all on the left. Since then, I've tried it both ways, in both BM doubles, and with my CCR.

I have settled on everything on the left, for both BM doubles and CCR. I feel less restricted in my movements that way. I don't have to worry about encumbering my long hose. It's easier to access my right thigh pocket, which is where I keep things I'm more likely to need during the dive (versus less likely, like a backup mask, which goes in the left thigh pocket). And it solves the problem I would otherwise have of managing my camera or scooter. I have a D-ring on my right side waist belt and that is where I clip my camera, or, if I'm diving with my scooter and want to clip it off out of the way while I'm doing something, I clip it there. I haven't yet done any diving where I have taken my scooter and camera in at the same time.

 

[Searcaigh]

Then that would be choice number one "Heck no, I don't prescribe to that antiquated, inappropriate system."

Well no it isn't because that's not what I'm saying.

If someone was taught to use deco stages on each side then I don't have a problem with that.

 

[helodriver87]

** GUE have their own 'customised' version of the JJ rebreather which has been modified to emulate a DIR rig, so has a longhose bungeed backup, all stage and bailout cylinders left, etc. Will leave that to a GUE proponent to explain.

It's basically a standard doubles rig attached to a breather. Rationale being that you fall back on what you're familiar with in an emergency. For GUE, that's doubles. So if you bailout, you're bailing out to a configuration you know very well. Stages are easy, it's a CCR, so they're all floaty with helium outside of your deco. Easy enough to leash and carry on left. Dilout setup makes it easier to use dil for things like validating cells/flushing, recovering the loop, etc without running a 3L dil bottle dry. eCCR because it'll actively maintain a breathable loop, no dil mav. Just ADV. The only add button you have is for O2, but that can be repurposed for offboarding bottom or deco stages. It's a great setup for boats and open water. Ok for caves, but the 50s can be limiting and drive you to lots of stages for bigger dives. Long hose/necklace (and appropriate planning) makes mixed team diving feasible with a good buddy who understands the unit (not taught in class, but something I've learned to appreciate since the GUE CCR community isn't huge and I don't live within 500 miles of another GUE JJ diver).

 

[Wibble]

Interesting there's no dil MAV, relying upon the ADV. How are dil flushes managed (or is the ADV manually operable, a-la Inspo)?

Having the dual 7's for diluent seems a good idea for shallower dives - say 30m/100' - where you won't need another bailout cylinder.

Beyond that it's stage city, just like every other rebreather diver