Hi. Diving Bill here. I'm looking for several things. First off...I need to find two underwater electric trolling type motors that will withstand at least 100 ft depths. I also need an underwater control module to be able to control the off/on and throttle of the electric motors. Looking for as heavy duty maximum output electric motors as I can get.
I also need any help I can get about constructing a waterproof compartment for the 4 batteries in the keel and the diesel engine compartment. Being concerned about hydrogen seepage from the batteries, I would welcome any advice on what kind of batteries to use that would minimize that. I have heard of hydro caps which are a catalyst that changes the hydrogen back into H2O and O2, but they are a bit of a pain to deal with. Also seen the hydro bags that you can put in the battery compartment that absorb the hydrogen and change it to water and O2 much like a dessicant bag absorbs water. It's not an exact term for what they do but I label these methods as "scrubbers".
I recently heard of another very new method to eliminate the hydrogen gas danger called oil filled pressure compensated. From what I know there is oil poured around the inside of the battery compartment and the watertight top of the compartment has a slight slope in it to allow the hydrogen gas to bubble up to that slope and then be exhausted to the outside. I do not know exactly how all this works, just heard a snatch about it today from another friend who is building his sub in Tampa, Fl. But it sounds very promising. No hydro caps or bags to deal with and hydrogen gets exhausted outside the sub.
Finally, I am seeking a small but powerful deisel engine and information on how to seal it watertight and install a snorkel to supply air to the carb. I also need to locate where I can get the snorkel valve that goes topside and prevents water from coming down the snorkel.
Any advice or suggestions you might have about all the above would be appreciated.
The board is green and we have pressure in the boat.