[PSUBS-MAILIST] Oxygen, Energy and Propulsion

[TeslaTony@aol.com]

Recently I've been working on designing my own PSub, but am having a few 
problems on a couple fronts:

1. I want to be able to go under and stay under for a long time, and so far a 
CO2 scrubber and a couple O2 tanks seem to be the best bet. However I can't 
find any formulas on how much of what chemical I need for the scrubbers, how 
much O2 will be needed for how long and what sensors should be used to detect 
the O2 and CO2 levels.

2. Energy: I know that a common system is a Diesel or Gasoline engine and 
batteries or just straight batteries. But the typical Lead/Acid car batteries 
leak when upside down, and in the event of some big emergency where the sub 
is flooded and you have to get out the batteries may be flooded as well, 
creating a major problem to you and surrounding marine life (not to mention 
causing problems while the sub is being retrieved). The other battery choices 
would be Gel-Cell (More expensive than Lead/Acid, but less dangerous), NiCad 
(expensive, heavy and not much storage capacity), Lithium Ion (heavy, 
expensive and may not come in the right size, but lots of power) and Plastic 
(lighter than most batteries, but if I had enough money to get them I 
wouldn't be asking you guys about all this stuff, I'd be hiring a 
professional engineering firm to design everything for me).
 Now this might sound crazy, but could there be an engine with an onboard O2 
supply for it to burn? Or even crazier; Could you just give it "gills" to 
"breath" the O2 in the surrounding water?

3. Most PSubs seem to have a single propeller in the back of the sub, which 
is one of the simpler systems (clockwise for forward, counterclockwise for 
reverse doesn't get much simpler), but is fraught with its several problems 
(entanglement is one, but also if the sub does a barrel roll in the wrong 
direction can cause a loss of power).
 I imagine many of you are also familiar with waterjets (like on ski boats) 
and how efficient they are, especially at high speed. Now my question is; how 
practical for a sub are they? Are they efficient enough to be used from 
battery power? What about machining? Could an at-home shop make the parts or 
be bought from an appropriate supplier cheaply? Are they reliable at all?

Thanks for the help,
Anthony