Primary and Secondary Regulators w/ dual Sidemount

[kwinter]

I'll jump in since I haven't given Dan and Tom a chance to yell at me for a while.
1. Backmount twins do not have to be manifolded. Independent twins were being used long before sidemount became popular and there are still some circumstances where they make sense. But I didn't dive them the "balanced" way that sidemount should be done. I used my left tank for descent, ascent, and any deco or safety stops. Right tank was for bottom time. After the dive I had plenty of gas remaining in the left tank. So I would swap out the right tank and be ready for another dive. I could do 2 long dives on 3 tanks or 3 dives on 4 tanks, even being a gas hog. But as I said, that's not the recommended approach for twin tanks.
2. In the beginning there was one tank and one short hose. Then came double tanks manifolded with a single outlet, and still one short hose. At some point, they became dual outlets requiring 2 regs and 2 hoses, and someone figured out that a long hose might serve as a good donation tool. Along comes sidemount and people try to fit a square peg into a round hole instead of looking at the picture from scratch. Diving with 2 long hoses makes infinite sense from that perspective. Stuff the hoses rather than wrapping around your neck and a long hose is always available right from your mouth. I am absolutely convinced this is the way sidemount would have developed if it had come before back mounted doubles and DIR.
Come on, boys. Let me have it.


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[victorzamora]

Diving with 2 long hoses makes infinite sense from that perspective. Stuff the hoses rather than wrapping around your neck and a long hose is always available right from your mouth. I am absolutely convinced this is the way sidemount would have developed if it had come before back mounted doubles and DIR.
Come on, boys. Let me have it.

Said like someone that doesn't dive sidemount

It doesn't make "infinite sense" at all. The biggest reason to wrap the hoses around your neck are for donation, you already have some slack. If you dive it the way you're describing, you have to actually release the long hose from the hose retainer before your buddy can breathe off of it. The way Edd/SteveB/SteveM teach it, you donate with some slack, and THEN pull the hose out of the hose retainer. Also, this doesn't require backwards regs for your left post. Plus, I don't understand why people find it so friggin' difficult to donate the long hose. If you're breathing your short hose, donate the other. If you're breathing your long hose, donate IT. The muscle memory for donating doesn't require learning it with both hands with my way, either....which is just another benefit. Also, when swapping to a single-tank setup, it doesn't require getting "creative" to route things....you just merge them together.

Honestly, I see ZERO benefit in diving twin long hoses.

 

[tbone1004]

not going to get anything from me. That gas management makes sense in ID's where you don't have the lateral instability inherent with sidemount tanks, so you're going to use a few hundred psi out of the left bottle, on descent as well as your wing inflation, so that makes sense.

On the discussion of two long hoses I'll disagree with you but only partially. My standard donation is to donate whatever is to allow the person to yank whatever is in my mouth, out of it. If I am on the short hose which is the left for me, and I get a low or ooa signal, then I switch to the long hose. If I can't, then the diver gets my short hose, situation gets resolved, and then he gets the long hose for single file departure. In open water, it is a pair of 36 or 40 inch hoses which is enough for open water ascents where I am less apt to give them the full length of the 9' hose that lives on my right side.

advantage of the donating the hose in your mouth goes back to the original reason why we have the long hose on our primary, you are donating a regulator in known working condition. If you are on the short hose and just hand me your long hose, A. the housing is flooded, so if I'm really out of air then I have to use the purge button which adds stress to the situation, and B. it may have something blocking the spring or grit stuck in the diaphragms or whatever else causing the potential for panic to progress. Less imperative in full sidemount teams or technical diving where sharing air really shouldn't happen, but in OW situations I don't want to risk it, so I have my hoses set up to always donate the hose in my mouth and switch once everything has calmed down.

Not feasible on non-reversible second stages due to hose routing issues, but the above logic is sound and is the whole basis for why the long hose was put on he primary instead of the secondary in the first place. That all said, in true sidemount teams you can pretty much ignore this consideration because you should never have to share air, the odds are so infinitesimally small it is not worth making a gear alteration to screw with it, but in recreational and mixed team diving, it is important to be able to get that regulator to the diver and know 100% that it will breathe on the first inhale, which is why we train for all of our divers to pass mouthpiece down so the housing is clear before the OOA diver receives the regulator

 

[kwinter]

I'm with you, T. It would be nice if all donations were "requested" but the reality is that you have to be prepared for the OOG guy who rips the second from your mouth. Maybe you can hang on to him and then switch him to the long hose after he settles down. And maybe Victor is always aware of which reg he has in his mouth or where the long hose is. But I just don't see it as completely necessary. It works, and I'm not criticizing it. But it also works with 2 long hoses. And I guess "long" is a relative term. I use 5 footers instead of 7s. And tbone using a 9 footer must be making up for other shortcomings in the "size matters" department. As for deployment, it takes no effort at all to release the hose from retaining bands, especially when some jerk rips it out of your mouth. And I have left side and right side configured regs anyway, so using a left feed second stage is not an issue. My regs are set up for CCR bailout and I can use them just as they are for OC sidemount. If I had gear strictly for OC sidemount, I might choose a different configuration. But 5 foot hoses, stuffed, switchable seconds, and different firsts for left and right so they can be identified by touch in complete silt out seems to be ok with me. And my experiment with inline valves instead of needing left and right seems to be working ok too.


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[victorzamora]

What does a 5ft hose buy you over, say, a 40" hose?

The reason tbone uses a 9ft hose is he routes his long hose downwards first on non-turreting first stages so he HAS to keep some slack. And with me and a 7ft longhose, a single-file gas sharing exit on a 7ft hose requires you to act as my suppository. With the required loop downwards, 7ft would never cut it.

As for donations being "requested"....you should check yourself if a) you dive with buddies that don't track their gas, b) your situational awareness is poor enough that you're just sitting there twiddling your thumbs when someone is swimming at you furiously. ESPECIALLY in sidemount, you should have TENS OF MINUTES of notice before an air-share is a feasible thing. In OW, on one tank, diving with a rec-only buddy, I can see the benefit of always having the 7ft long hose in your mouth....but with one tank that's all I ever breathe off of. With two first stages, there's no benefit of two 5ft hoses.

 

[tbone1004]

the real reason I use the 9' is because my buddy, cough cough the knucklehead who posted above me is 6'6" and while I like him, I'd prefer not to be stuck in his crotch if he has to steal some of my gas.... I'm 6'4" so I prefer my buddies have at least 7 so they don't have the issue of being in my knees. The 9' allows a bit more separation and in sidemount with the hose stuffed it doesn't really matter. 7' is pushing the limit for most people on what they can manage in a loop.

two 5's I don't really agree with because they are too short for people my size to actually share air in single file. I have a deployable short hose that they can have until things get situated, but the reality is I won't give you a regulator until I have firm control of your harness, and I won't let go until you have calmed down, so at that point you can switch stages.

 

[Subcooled]

"choice of which regulator to use as a primary regulator seems to be complicated a bit when the cylinders are used in a sidemount configuration. Since the cylinders are no longer connected with a manifold, they no longer act as a single gas supply but rather two independent gas supplies under normal conditions. As such, it seems that utilizing the long-hose as one's primary regulator is not such a clear choice, and factors other than the speed at which you can donate the regulator come into play. Here is why:

In sidemount configuration (which is dictated by a low ceiling) you must use two independent cylinders. UTD has a very technical solution to allow for an isolation valve, but let's assume that it is not available. This means that you have to swap regulators every X minutes. There are two cylinders. There is NO PRIMARY cylinder or regulator. You will use them both 50% of the time. In a gas sharing situation you have 50% chace of having 180cm or 210cm of freedom, or a 50% chance of intimacy. If you happen to breathe the shorter hose, then just give it, be intimate for a moment, and swap to a loner hose. Simple. No problem.

 

[Dhboner]

Of course a really cool solution is to make a point NOT to dive with anyone who would put themselves in an "out of air" situation in the first place...just saying

 

[kwinter]

Victor - I have had 2 instances of an OOG diver grabbing me for gas. Neither one was a buddy I was diving with, and neither one gave me any warning whatsoever. Both were on wrecks, not caves. Coming around a corner or up through a hatch and I just got grabbed. So forget about someone nicely coming up and asking "may I." As for your question about what a 5 foot hose gives me that a 40 inch hose doesn't, I have to give you my math teacher answer of "20 inches." A 5 footer will handle most situations. If there was a narrow, single file exit required in a gas sharing situation, I would probably just swap or donate the bottle. But I have no objection to using two 7 footers as long as they stuff neatly on something as short as an LP45.
I refuse to make any comment about being close to your or Tom's crotch.


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[Sidemount_Stu]

advantage of the donating the hose in your mouth goes back to the original reason why we have the long hose on our primary, you are donating a regulator in known working condition.

You're not wrong, however this comes from backmount where potentially the backup reg may not have been used for many many dives, other than a brief "buddy check".... with sidemount, the short necklaced reg has been used regularly and is a much more "known" piece of equipment.

If you are on the short hose and just hand me your long hose, A. the housing is flooded, so if I'm really out of air then I have to use the purge button which adds stress to the situation

This is the same situation for any OOG scenario, whether the donated reg comes from your mouth or stowed. The second it leaves your mouth it floods and will require either a breath or the purge button to be used to clear it. This is a standard part of any OOG scenario, it's irrelevant whether the donating diver is on backmount, sidemount, singles, the reg will also flood on exchange.