Submersible pump motors

[redboat219]

Bob Gaito uses a couple of these 6v submersible DC pumps to fill and empty the ballast tank in his Atlantis sub https://forum.rc-sub.com/forum/build...ises-and-dives


these pumps could also be used as a means of propulsion like on the Proteus from Fantastic Voyage or as thrusters.
my question is, can they be modified to drive the propeller shaft on a conventional boat like a Skipjack?
how about speed control?

[type7]

I don't think they are reversible.