RE: Drive system for LARGE Boat
Some years ago a German boater was building a 4m model of the Bismark, if memory serves me well.
It had three or four propshafts, each powered by two belt reduced Bosch startermotors, that's eight(8!) motors...
The motors were controlled by custom built controllers, and a massive amount of deep cycle batteries.
With all that weight the hull still needed waterballast to reach the intended waterline.
It sailed just like the real thing.
If you're interested, I can try to dig up the article.
Regards, Jan.