Off boarding your gas on the o2ptima

[dragerdiver]

I am going to be traveling to a remote part of the philipines, and am thinking about diving my optima with off board 80's for dil and O2. Has any one tried to off board their gas' and how did you do it? How about using a smaller frame to make the unit smaller than it all ready is?

Thanks
Lee

 

[Uwe Sieg]

I converted my unit to BMCL (Back-mounted Counter Lungs). The inflation valves I use have a rotating omni-directional plugin valve which I use for both offboard O2 & Dil.
I think the best way to use off board Inflation would be to utilize a longer hose which can be fed securely to the wing inflation valve.

 

[moose_grunt]

Advanced Diver Magazine ezine issue #4 talks about this in general in an article starting on page 3. I've considered something like this for my Inspo as well, for the same reasons. Essentially you'd need to run whips with QD's from the sidemount first stages to QD's on whips connected to your O2 and/or dil manifolds.

Another option would be to keep the on-board tanks, plumb in off-board to MAVs, and drive the unit with MAVs as much as possible (leave the controller on low setpoint, and use MAV to maintain high setpoint). This seems to have a couple of advantages:

• Not needing to drop a few hundred dollars on hardware such as QD, check valve, manifold, hoses, etc.
• You are not 100% dependent on the off-board, so can take them off for convenience at entry and exit, without worrying about it
• More redundancy. If on-board and off-board are separated, you have two distinct systems on each side with their own hoses and first stages. If you go totally off-board, you only have one system on each side. If a hose goes or a first stage craps out, you're in a lot worse of a place (options-wise) than if you could just plug in your completely independent off-board.

These are just my thoughts on the topic, having gone through the same scenario recently. Ultimately, we just decided to keep on-board , but run the units off off-board connected directly to the MAVs as much as possible. It would have been less hassle, time, and money, for the space savings of a few small CCR bottles. Then the whole thing got postponed until next year, so we never got to put our plan in action beyond a few training dives.

Jim