RB 80

[Chuck_Northrup]

Dirk,

As DRE already clarified, the "oxygen problem" does not exist. The RB80 is SCR not CCR. The highest PO2 gas you could possibly breathe is based on the analyzed FO2 in the bottles you have plugged in. The back gas consists of two cylinders of whatever size you prefer. They are connected by a manifold so the gas would be identical in both cylinders. I have heard of divers side mounting the system and therefore removing the manifold, but I am not sure if that reflects the true design of the unit. The efficiency of the RB80 would make AL40's the equivalent of almost 400ft3 of gas. The only time you would plug in an oxygen whip is when you where doing deco, and of course you would be at the appropriate depth to avoid O2 issues.

Features like a 10 hour canister (the longest duration for a "stock" unit) and the moisture removal process reflect the RB80's design fundamentals (cave exploring). DRE's example of the scooter and bottle laden RB80 diver is fairly accurate. With the RB80 you would need to carry a separate bottle for every gas you wanted to breathe. The real advantage here is getting more time out of your cylinders. The true role of the RB80 is as a gas extender. The same benefits can be produced on a CCR with fewer encumbrances, and if a Halcyon CCR is released I am sure it would be an interesting unit. If a CCR with the same intuitive operation and rugged construction of an RB80 were available I think GUE would endorse it.
   
I feel people can be too quick to dismiss the RB80, partially because they dislike the people associated with it. The truth is there are as many "benefits" as "drawbacks" to the RB80 and there is probably enough demand for it to increase its presence in the rebreather market.

Chuck