Originally Posted by guitarguy56
These look nothing more than glorified trolling motors with the proper pitch props...
And said proper-pitch props matched to an efficient alternator, which in turn is matched to the fluid speed it will operate in.
Exactly right. But all
those conditions have to obtain for a hydro-gen (or wind turbine) to create meaningful amps. Ya can't just use a thrust propeller attached to any old DC motor intended to spin at a totally different RPM range and expect good output. The Watt&Sea is, indeed, basically a reverse-engineered trolling motor. But it's a very clever one, and probably about as optimal as you are likely to see, anytime soon.
Could you reverse the current & use it as an outboard? Probably. It wouldn't move your dinghy real fast, tho. Could you change to a different prop and use a digital controller to optimize it for outboard use? Ah. That's the question under discussion, here. I think you could, with some (acceptable?) sacrifice of performance in each mode. But the point is, the unit would need to be designed from scratch as a dual-purpose machine, and you could not use the same prop in each mode. Begin with those criteria and realistic performance goals, and you could probably build one. And make a small fortune... into a much smaller fortune.