Odd question to start with.

[Simon.O.]

There are a few variables here.
If a boat is going "slow" like a retrieval boat, then it should not need water cooling.
In saying that I have managed to trial water cooling on my big tug with the water pickup right behind the prop in a very similar fashion to my FE hulls.
That has since been pulled out and I have gone with lower loading on the motors and good old fashioned air cooling with the assistance of a PC cpu fan.

[dplin2001]

Thanks, I'll start looking for air cooled stuff for this project.