kerosene

With salt water it will be fouled in minutes.

:confused: salt water inside the motor. Sound like the worst possible idea. With this idea, I could use a thermal heat exchanger...

From an engineer that has spent over 50 years as a heat transfer specialist: For this condition, a heat exchanger has resistance to heat...

20x30 is very small. Hard to keep going straight in even tiny waves or ripples. Where will it be tested? A pool? Catamaran will be...