Advice, hose routing for mirrored left and right second stages

[tbone1004]

@Squid88 as someone who has been sidemount cave diving for 8 years, I have yet to see an argument for hoses not put behind your neck that holds water

for "normal" right handed regulators, the hose is hog looped. This has the advantage of making air sharing and restowing the hose much easier. Your long hose for donation needs to be on whatever side the second stage is fed from in order to prevent hose crossing under the diver. There are two options for this. Hog loop it, or have it come straight up from the tank. Straight up has a few big downsides as mentioned above.

If you put both hoses behind your neck, either crossed or both going in the same direction, you can only donate one hose as one will always find a way to cross. That hose needs to be put on second so it is on top.

The two smallest "sects" of sidemount divers donate from the mouth always. One is the Toddy Style divers who don't use long hoses and like to donate tanks which is not accepted in cave diving. The other is the UTD Z-system, which is an equipment solution to a skills problem.

As you don't have non-directional regulators, and they are not common to use, going in depth on those is probably not worth going down.

As one who used to use lefty/righty regulators and no longer do, I would recommend you find another 109 body and use that. That has no bearing on my wanting your lefty body, and everything to do with it just not being a great option for sidemount diving. Lefty regulators are great for deco bottles if you subscribe to left lean/right rich, or you don't want to loop the deco bottle behind your head for whatever reason on the left side. Other than that, they don't really have much use

 

[Squid88]

@Squid88 as someone who has been sidemount cave diving for 8 years, I have yet to see an argument for hoses not put behind your neck that holds water

for "normal" right handed regulators, the hose is hog looped. This has the advantage of making air sharing and restowing the hose much easier. Your long hose for donation needs to be on whatever side the second stage is fed from in order to prevent hose crossing under the diver. There are two options for this. Hog loop it, or have it come straight up from the tank. Straight up has a few big downsides as mentioned above.

If you put both hoses behind your neck, either crossed or both going in the same direction, you can only donate one hose as one will always find a way to cross. That hose needs to be put on second so it is on top.

The two smallest "sects" of sidemount divers donate from the mouth always. One is the Toddy Style divers who don't use long hoses and like to donate tanks which is not accepted in cave diving. The other is the UTD Z-system, which is an equipment solution to a skills problem.

As you don't have non-directional regulators, and they are not common to use, going in depth on those is probably not worth going down.

As one who used to use lefty/righty regulators and no longer do, I would recommend you find another 109 body and use that. That has no bearing on my wanting your lefty body, and everything to do with it just not being a great option for sidemount diving. Lefty regulators are great for deco bottles if you subscribe to left lean/right rich, or you don't want to loop the deco bottle behind your head for whatever reason on the left side. Other than that, they don't really have much use

Thank you I appreciate your insight.
I do have another 109 converted 156BA I can use and route the hoses on the same side or as mentioned I could just cross one from either side around neck and have a dedicated donating regulator that always sits on top.

I'll think about it some more and play around with it some. I really liked the idea of not having a hose around my neck and keeping things more clean but maybe there's too many downsides.

 

[Kevrumbo]

. . .
. The other is the UTD Z-system, which is an equipment solution to a skills problem. . .

No. . . You can rail & protest about the perceived complexity of the Z-system as you understand it, but it has nothing to do with "an equipment solution to a skills problem" as you rhetorically contend.

UTD Z-System Sidemount is a necessary solution and equipment adaptation utilizing a Distribution Block or Z-Isofold/Manifold along with QC6 cylinder plug-ins in order to retain the consistency of the DIR Long Hose Paradigm: The Long Hose Primary Reg on Open Circuit is always donatable from the mouth per OOG protocol, and the Secondary Back-up Reg is always there bungee'd around the neck. There is no switching between regulators as in classic Independent Doubles technique.

 

[leadduck]

It's not that it's more likely to get entangled/snagged....it's that you lose it completely if it does. With a longer hose, you are more likely able to still reach it if it gets snagged.

now I wonder if we're talking about the same thing ... in a long and very narrow restriction a short hose straight from a sidemount tank to the mouth is less likely but still might snag a protrusion, but if it does so then the problem is at my chest where I can easily fix it. Whereas the long hose loop behind my neck and/or between my knees is not only almost guaranteed to catch everything in its way, but worse, the problem will be between my shoulders or somewhere between knees and ankles where I can't reach. I'd have to move backwards, which I might fail to do in a tight spot, and so lock myself.

In a cave in a single-file air sharing situation (the reason for longhoses), you have one diver immediately behind the other.

That's the point I think. With "very advanced cave divers diving extremely narrow restrictions" I meant restrictions that are so long and narrow that single-file air sharing on a long hose is impossible. I thought of pure sidemount teams who consider swapping tanks the only possible way of air sharing during an exit.

 

[leadduck]

My big issue with two 5-ft hoses is that they're useless to me. I'm 6'6" and BARELY am able to use a 7ft hose.

Isn't the receiving diver swimming in front? So if you're extra tall, your hose length doesn't matter for single file swimming, whereas your buddies' hoses must be longer. A 5' hose is of course useless for single file swimming, it is for openwater or in a cave for temporary air sharing before swapping tanks.

 

[Dan_P]

The two smallest "sects" of sidemount divers donate from the mouth always. One is the Toddy Style divers who don't use long hoses and like to donate tanks which is not accepted in cave diving. The other is the UTD Z-system, which is an equipment solution to a skills problem.

I'm guessing the manifold concept is probably about as accepted in sidemount now as it was in backmount circa 1989...

Meanwhile, the bulk of conceptual reasoning for implementation of a manifold, are universal across systems whether the tanks are positioned on the back or side.
The big difference is that tanks bolted onto a backplate can't be swapped around anyway, thus making valve side HP connection the reasonable choice so as to connect all the gas and eliminate the need to open/close valves, at the expense of complete gas loss in the event of a leakage.
Sidemounted tanks aren't bolted down, so that's a significant difference - but that impacts "how manifold" far greater than "whether manifold".

The reasoning for Z system is founded in a rationale of scalability and consistency, which one might agree with or not.
What it is not based on, is popularity in an industry-wide kerfuffle of opinions on what is "right" in the world of sidemount.

As for "skills problems", have you honestly inferred there is an organization-wide lack of skill in UTD?

 

[victorzamora]

The reasoning for Z system is founded in a rationale of scalability and consistency, which one might agree with or not.

It's cool that it's consistent. It's kind of weird that you turn off and on tanks every 300psi while diving backmount doubles, though.

 

[victorzamora]

now I wonder if we're talking about the same thing ... in a long and very narrow restriction a short hose straight from a sidemount tank to the mouth is less likely but still might snag a protrusion, but if it does so then the problem is at my chest where I can easily fix it. Whereas the long hose loop behind my neck and/or between my knees is not only almost guaranteed to catch everything in its way, but worse, the problem will be between my shoulders or somewhere between knees and ankles where I can't reach. I'd have to move backwards, which I might fail to do in a tight spot, and so lock myself.

You're definitely envisioning something different than I am. With a straight-up hose routing, you can't lose as much length without it being a problem as if you had more slack...right?

With behind-the-neck, I doubt you'd snag a reg hard enough and long enough that you'd pull it backwards behind your neck, then left across your back, then forward over your shoulder, then continue pulling down. That's a lot of convolution to get the reg out of reach. With straight-up hoses, you don't get that. If the hoses get pulled, they get pulled out of reach.

That's the point I think. With "very advanced cave divers diving extremely narrow restrictions" I meant restrictions that are so long and narrow that single-file air sharing on a long hose is impossible. I thought of pure sidemount teams who consider swapping tanks the only possible way of air sharing during an exit.

I know VERY few cave divers that would consider swapping tanks a good, much less the only, way of exiting. I have never in my life been tempted to donate a sidemount bottle and have never heard a sane reason for attempting to do so. I think you'll find a very small portion of cave divers that are okay with that concept....my buddies and I certainly are not.

Isn't the receiving diver swimming in front? So if you're extra tall, your hose length doesn't matter for single file swimming, whereas your buddies' hoses must be longer. A 5' hose is of course useless for single file swimming, it is for openwater or in a cave for temporary air sharing before swapping tanks.

Absolutely the OOA diver is up front, I thought my post was clear on that but I apologize that it wasn't. My issue is that if I'm diving with you and YOU have a 5ft hose.....I can't count on you for help. Swapping tanks is simply not feasible, so you've now doomed me. In open water, I have yet to hear an argument for 2x5ft hoses that I buy.

 

[kensuf]

My big issue with two 5-ft hoses is that they're useless to me. I'm 6'6" and BARELY am able to use a 7ft hose. A 5ft hose would mean you'd need a 4.5ft tall diver to be in proper single-file with, or you'd have to dive some configuration where the divers were stacked on top of eachother...which isn't always possible. 5ft hoses don't help for air sharing any more than much shorter hoses.

I find discussions of 5' hoses in sidemount interesting.

If the majority of people agree that you should have a 7' hose on backmount doubles for overhead (cave/wreck) penetration in order to share gas, why would anyone use a hose that is 2' shorter coming from a valve that is also an additional 12" farther away from your out of gas buddy?

Everyone diving in an overhead needs a single 7' hose for gas sharing.

 

[Dan_P]

It's cool that it's consistent. It's kind of weird that you turn off and on tanks every 300psi while diving backmount doubles, though.

Consistant with differs from identical to, obviously.
I believe I've been clear in post #16 explaining the why behind valve-side vs. stage-side manifold in sidemount/backmount, respectively.

Do you even see any real problem in isolating the tanks on the LP side of the stage as opposed to the valve?