Sidemounts and Manifolds

[Mark Michaud SELAUSAR]

Those are all great questions for the diver in question, with the blocked sidemount tanks. He's not on the board, so don't hold your breath for answers.

Why's he doing it? Maybe just to get a little extra gas off a tank with a regulator malfunction? *shrugs* Sure, diving independants correctly we'll yeild you enough gas to get out(especially with a little extra conservatism), but there's nothing wrong with a little extra gas still.

Matt's right. I have seen it a few times but not enough to duplicate it, or I would likely make one.

 

[Cave Bum]

My question is, what prevents a side-mounter from hooking up a manifold using an extension hose, something like the doo-hickey Halcyon uses for bailout with its RB-80? Are there some massive disadvantages for using an extension hose? Is it that any cave with restrictions tight enough for side-mounting necessitates removing the tanks at some point? Is the hose too vulnerable to entanglements or rupture?

The point of sidemount, in addition to being able to go through passages too low to use back mounted doubles in, is to be able to remove your tanks and push them through a restiction.

They are also used in solo diving as a redundent system, however most folks who use it that way will have an "H" valve on at least one of the tanks with a spare reg setup. That way if you loose a first stage on either tank you can use (or move) the spare reg setup to the tank to replace the bad regulator.

Maniflolding would defeat both of those purposes.

One thing to keep in mind, sidemounting is just one tool in the toolbox. Not every dive is best done with sidemount. It is useful where appropriate but backmount is also useful where appropriate. They each have their own places.

 

[Mark Michaud SELAUSAR]

The point of sidemount, in addition to being able to go through passages too low to use back mounted doubles in, is to be able to remove your tanks and push them through a restiction.

They are also used in solo diving as a redundent system, however most folks who use it that way will have an "H" valve on at least one of the tanks with a spare reg setup. That way if you loose a first stage on either tank you can use (or move) the spare reg setup to the tank to replace the bad regulator.

Maniflolding would defeat both of those purposes.

One thing to keep in mind, sidemounting is just one tool in the toolbox. Not every dive is best done with sidemount. It is useful where appropriate but backmount is also useful where appropriate. They each have their own places.

There are also other reasons for sidemount. I, for one, am getting older. Being able to carry each tank, singly, to the water, or off the boat, saves my knees and back. It also reduces exertion before and after a dive. This will, hopefully, prolong my diving years and keep me safer. I find that s/m balances really good in the water too. If I do go into low places (I do) it is also the perfect setup during any dive. The manifold we have discussed can be unhooked easily, adding two more small moves, if a diver needed to remove tanks. As diving is ever evolving, reasons and methods will continue to evolve for any configuration. Open minds will definitely makes us more safe and provide other options for safety and enjoyment. This is not to dispute what you are saying, just giving another perspective on this topic. Bottom line is this, we have to be able to manage our equipment or it does no good for us.

 

[SuPrBuGmAn]

I dive sidemount, for the most part, because it sucks pulling doubles out of my boat.

 

[Dive-aholic]

They are also used in solo diving as a redundent system, however most folks who use it that way will have an "H" valve on at least one of the tanks with a spare reg setup. That way if you loose a first stage on either tank you can use (or move) the spare reg setup to the tank to replace the bad regulator.

While I've heard of this, I have yet to see someong with an H valve on a sidemount tank. It really isn't all that common. Most sidemount divers dive with a traditional valve. Oh, and I'm one of those that uses the reason of a redundant system for solo diving (no H valve on my tanks).

I dive sidemount, for the most part, because it sucks pulling doubles out of my boat.

So it has nothing to do with those river caves you keep visiting...

 

[GLENFWB]

So it has nothing to do with those river caves you keep visiting...

Rob, it has to do with the fact that he knows he just looks so dang cool in sidemount...at least that's what Bugman says!

 

[SuPrBuGmAn]

So it has nothing to do with those river caves you keep visiting...

Thats where the "for the most part" comes into play.

It also covers the looking cool part, but Glen has just posted proof of that fact :cool2:

 

[JDostal]

I don't cave dive, so this question sprang fully-formed from a vast pool of ignorance on the subject. But in a thread about a PADI Side-mounting Distinctive Specialty, somebody mentioned that side-mounted tanks are always independent doubles.

My question is, what prevents a side-mounter from hooking up a manifold using an extension hose, something like the doo-hickey Halcyon uses for bailout with its RB-80? Are there some massive disadvantages for using an extension hose? Is it that any cave with restrictions tight enough for side-mounting necessitates removing the tanks at some point? Is the hose too vulnerable to entanglements or rupture?

Just curious, really. But has this been tried and found wanting??

It really negates one of the major advantages of sidemount in that you DO have completely independent air supplies. Sidemount was originally intended as a specialty gear config for diving tight cave. When you are diving cave that NEEDS sidemount, buddy rescue is most often simply not an option. Self rescue is the name of the game.

Last year I was on a cave dive and was about 1000 feet into the cave. All of a sudden I heard an explosion and a roar of air. My regulator hose on the tank that I was breathing had blown off the 1st stage.

Not a big deal in sidemount. I swapped regs, shut down the tank and thumbed the dive and started swimming out. I was in big cave on this dive and could have requested air from one of my dive partners but there was no need.

I guess if you were using sidemount to help with physical limitations in open water only you could link the tanks using some sort of HP hose. I think the Halcyon rebreathers used to link the two tanks using a setup like this? But really it is a lot of cost and convolutedness to avoid just switching a reg a few times during the dive.

It will make the tanks a PITA to put on and take off. It will be extra crap cluttering your chest.

It would be feasible but not something I'd ever recommend.

 

[wedivebc]

I have been an advocate of independant doubles for years. The increasing popularity of sidemount has caused many to realize what a useless piece of equipment a manifold really is.

 

[ShagMan]

I have nothing to add to this discussion, other than to say "what a great discussion!"

I will be swapping to sidemount shortly after my cave classes for the same reason Mat and spd135 posted, I have a type of early arthiritis (ankylosing spondylitis, dang bad genes!) so I don't want to carry two silos on my back a lot.