Re: Keel cooling
I've had keel coolers on workboats but they had exhausts that went up vertically through the deck. A small keel cooler would create very little drag but you'd still need to keep a wet exhaust unless you could devise some sort of exhaust exit that wouldn't melt lines or sails. Fumes might also be a problem. On workboats you're usually in the cabin when motoring and the exhaust pipe is pretty high.
Alberg 35: With a philosophical flourish Cato throws himself upon his sword; I quietly take to the ship.