Donating a cylinder in an OOA

[phillip1]

I think that's a potential concern.

Especially gven the number of times I have heard/read some sidemount divers justify not carrying a long hose on the basis that they could just hand off a bottle. In my opinion it becomes a more likely concern when it is combined with a reg switching schedule that is a little haphazard and does not ensure the gas remaining in either tank is at least equal to the amount used to penetrate to the turn point.

In short, a combination of divers not having a long hose, diving to thirds and not using a well thought out shcedule that balances the gas near the turn point, would leave the divers at elevated risk, more or less requiring divers to hand off a cylinder when they might not have the time, gas, room, visibility or skill to do it efficiently.

In SM it is so remote that your buddy would loose all air in both cylinders, much more remote than a total BM gas loss, that is if all team members are in SM, you don't need to carry long hoses, however practicing the skill of actually handing off a tank is definitely needed and is really not very hard to do at all, if one finds it very difficult to do then you are either way to cluttered in config or should not be diving SM in the first place.
I bet many SM divers have never actually tried this skill and just like any other should be practiced.
In the one in a million situation were my buddy did loose all air in both tanks, I would hand off one of my tanks. With the Razor (I assume the Nomad and Dillo too) you are not off balance at all and I have done many many OW dives with one tank so swimming out would be no problem.

You need to plan gas accordingly of course.

What I have found is that I see no difference in having a long hose or not comfort wise etc.., true it could come undone (super unlikely) in very tight SM caves and be a hassle, but it has yet to happen to me so I ended up just always keeping a long hose, it cant hurt and I don't need to keep changing to a short and long when I dive mixed team.

[SuPrBuGmAn]

It doesn't matter which harness you are using, if you are diving steels, and you take one off, you'll get off balance. Not everyone is diving AL80s.

[phillip1]

knowing nothing of steels, would it be possible to swim with only one on? I am assuming it would be doable, but then again this is like a 757 loosing both engines at the same time.

[DA Aquamaster]

It doesn't matter which harness you are using, if you are diving steels, and you take one off, you'll get off balance. Not everyone is diving AL80s.

+1

I had a bungee break this weekend and until I reconfigured and got things squared away, I can assure you that having only one near full LP 95 attached left me decidedly unbalanced, and swimming, while possible would have been interesting and making the same speed and/or exiting with the same RMV is just not likely over any distance in the out of trim condition.

If a SM diver is going to hand off a SM tank to an OOA diver and is using steel tanks, the odds are good the process is going to have to include an exchange of tanks, not just a hand-off.

[DA Aquamaster]

but then again this is like a 757 loosing both engines at the same time.

I agree to an extent. With any independent doubles system, losing the contents of both tanks is very unlikely as it would require two separate failures in the burst discs, neck o-rings or regulators. But a long hose is handy even with a sinel failure.

Using a 5' or 7' hose on one of the tanks adds a great deal of flexibility in a variety of other situations from mixed team diving to just handing off a reg briefly while a team mate works a problem to overcome/adapt to a single failure.

And remember, if you are pushing thirds, and lose the contents of just one tank near max penetration (i.e only a single failure), the reserve is razor thin and it won't take much for that to come up just a bit short on the way out. In that case, I'd rather just hand off a long hose to the OOA diver for the last couple hundred feet than to try to exchange tanks. It's just a whole lot quicker and easier in an already stressful situation.

[Bobby]

It doesn't matter which harness you are using, if you are diving steels, and you take one off, you'll get off balance. Not everyone is diving AL80s.

IMHO a long hose is the best choice in SM, especially when diving mixed teams and mixed configurations. If a U style wing is utilized on the SM rig it is easy to balance a single steel even with a cave fill, I have many times. I have also taken the second cylinder off one side and clipped with the first putting both cylinders on one side. It does not balance well with full cylinders but is fairly easy to balance when they have been breathed down.

I agree that it takes practice exchanging cylinders and that it can be done if needed. For fairly deep dives we have used this system to get the bottom mix and weight off the deep diver. Having a long hose on SM though seems to solve a lot of likely bad scenarios with no real down side that I have found. I would go one step further and say that some of the stuff I have pushed that I consider tight and difficult is made easier with a long hose allowing cylinders to be moved further in front while working my body through.


Bobby

[b1gcountry]

I just chalk it up to the 'internet diver' thing.

[Dark Eternal]

I have just started to dive sidemount and have played around with removing cylinder a bit. I have only dove SM in open water for practice so far buy have tried a handfull of gear configurations. In a Razor harness I was using a few weekends ago with AL80s it would be very easy to do this. In fact I took a bottle completely off and swam around without it multiple times. It is a completely different story in a Nomad with Steels though. I have tried it with 85s and 108s, while I could remove the 85 for a bit it was awkward to say the least, the 108s it would have been pretty much impossible to feasibly do this.

In my humble opinion handing off a tank should be a last resort in most situations. As everyone has mentioned, it takes practice, like any skill. Most people have probably not practiced this and should rely on the skills (long hose donation) that they HAVE practiced in training extensively. I am as new at sidemount as it gets but I fully plan on keeping a long hose available for emergencies. It is nice to know that switching tanks is a possibility, however I can not see very many situations where it could be performed effectively enough to not make the situation worse than it already was - at least not with my level of experience and practice.

[SuPrBuGmAn]

...would it be possible to swim with only one on? I am assuming it would be doable, but then again this is like a 757 loosing both engines at the same time.

Sure, sideways, and very ackward and ineffecient. You could probably reconfigure the single steel from one side and across your stomach and clip off on the opposite side. Surely not ideal... I'll have to try that.


Its a fairly dumb idea... use a longhose :P

[phillip1]

I always carry an extra bungee in my pouch takes no room at all.
Also in handing off your tank you obviously would take your buddys empty tank, but then again with al tanks you rally don't need to. We have practiced this a lot in my pool and although I don't ever foresee actually having to do this it is (with al tanks) very easy and fast to do.