Sven, I'll put up the pics and I have my cables back, but i'm in a rush, as we need to go to CZ in like 30 minutes. I will also draw the schematics of the whole sistem, and advise on how to make your own units.

And that I'll do no matter if refferee's on the tournament likes my sistem or not. I belive its a good sistem, I need only to work on the fine details. Like how to make it lighter and easyer to use.

Sven, I'm not sure what you mean with SOS wizzle, I take it you mean the whistle that divers are carrying on the BC's. No, thats not it. Its special divers buzzer, that you mount between BC inflator hose, and the BC inflator (BC=Buoyancy compensator = Life jacket). Buzzer works on the "low preassure compressed air" in the inflator hose. Thats what drives the buzzer.

But yeah Sven, I work all the time with compressed air. I fill like 3000 tanks per year in my diving center.