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After reading all the hoopla about rebreathers, I got a chance to try out a draeger unit today. Very simple construction, not much visible hightech here. You have a 2 plastic bags and a plastic can which holds the sorbant under a open-front plastic shell. One tank of mix and a first stange is strapped under the shell. The shell has a holster attached on the right side for a 15 cuft. pony tank. One of the plastic bags has the constant flow module attached to it. The constant flow module is about the diameter of a hocky puck, twice as thick and has two LP hoses leading to the first stage. This is the bag downstream from the sorb cannister. A smaller bag is upstream from the sorb and attached to a valve similar to a drysuit auto-deflation valve. The top of the plastic shell has two holes for the mouthpiece hose. All of these various components are connected with quick-release o-ring fittings. There must be fifty o-rings in this thing. The upstream fittings all have red o-rings and downstream fittings have black o-rings. The sorb cannister is an oval can shaped affair with a t-bolt holding the lid on. Refill procedure is basically dump the old sorb out and pour the new sorb in, slap the lid back on. Check seals by putting your hand over one of the two color-coded connector tubes and blow then suck on the other. Once assembled the back of the shell is closed with a couple of cloth flaps. The sorb as a 6 hour life. The supply and exaust hose is also o-ring color coded and it uses a cylinder ball valve to open and close the mouth piece. It uses a larger than standard mouthpiece, so your favorite orthopaedic unit won't fit. The hose has flapper valves located adjacent to the mouthpiece for flow control and has arrows indicating the airflow direction. This unit is not set up for use with a BC, you don it like a back-plate. When you turn on the gas you can feel the bags inflating against your back. Once the air is turned on the clock is ticking, so you don't turn it on until the moment before you jump in. As the tank is on the bottom, the tank valve falls right to your left hand. The procedure with the hose valve is to hold the mouthpiece firmly with your teeth and one hand and open the valve with the other. The valve is quite stiff so you have to have a firm grip or you won't get it open. Diving impressions- Rebreather breathing is very different from scuba. You can breath normally without the mechanical blast of compressed air and then the forced exaust. I found it quite pleasant and possibly the most attractive feature of the unit. The unit was very lightweight with a low center of gravity. Did not try it with the pony, however. You can adjust your buoyancy by loosening or tightening the exaust valve. When it is tight, the air bags retain more air, thus more buoyancy. When you do this you tend to expel air with every breath rather than on every fifth breath which uses more air. When you go fast the hoses flap in the breeze to an annoying degree. The hoses have ring weights on them which you can adjust to reduce this tenancy. At one point my breathing became difficult, it turned out to be a kinked hose which I could fix by twisting the connections. Breathing was rather difficult when you rolled onto your back, due to the placement of the counter-lung in the shell. An interesting aspect of the rebreather is that you can breath as fast as you want without effecting air comsumption. Would I buy one of these? If I had a spare $6500, yes I would. I have a feeling that the price will drop once Uwatec sells a few. While under water, I could not help but feel that I was experiencing the future of scuba, wether some like it or not. Jim
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