Hi James. I'm using 4 Minnkota saltwater 101's. They will be pressure
compensated with air. I'm just not keen on the oil compensation method. A
scuba regulator and small tank located outside the hull will keep the pressure
slightly above ambient. Scuba tank compressors put very little moisture
into the air. I've been diving for years, and it's always a challenge to keep
your body hydrated when doing multiple dives. This is because each breath
removes moisture from your lungs. Actually, quite a lot of moisture. If you
dive 3 or 4 times in one day, you can get pretty thirsty! Of course, some dive
shops have better compressors than others, but with a little research, you can
find a good one for dry tank fills.
Speaking about air, I'm making a change to the body. I want to add two
additional scuba tanks to the outside, and to keep them covered so there's
minimal issues with entanglement. The pictures so far show the big fin on
the back end. I'm adding two rounded tubes to the lower fin area, so that
when the lid is closed there's room underneath for the two additional tanks.
The new shape isn't quite so smooth, but the extra HP air capacity is required
for the increased ballast tank size. I originally had enough room for the
small compensation tank just below the finned cover, so with a couple of "
humps" added, I can fit the two new tanks under there too. This is in addition
to the tanks inside the sub.
Well, better get back up to the shop. That thing ain't gonna build
it self. Frank D.