Hello Brian, and welcome...
the only motors that I have cooled were in my speedboats, and that was through a heat sink around the motor its self, the water pickup was just behind the Prop, and the outlet was on the stern...
all of my normal working boats, Tugs, merchant ships and the suchlike do not have any problems with heat..!
were is the heat coming from...?
if its from the motors or ESC, then I would suggest that you would need to change them for more efficient ones, that do not heat up..
