Cooling for airboat escs

I am building an R/C rescue boat with two airplane motors. The electronics are in a box that is mounted quite high above the water level. The speed controls are Seaking 30 amp and have water-cooling. Obviously, the water isn?t going to flow uphill and through the cooling jackets by itself.This craft will spend most of it?s time at low speeds and will be going forward and reverse.

Can I add a heat sink to the top of the controller? Then put a fan at the front of the radio box and blow air through it for cooling?

Or maybe a water pickup and then a pump to move the water uphill and then through the speed controls?

The KISS principle is of course important.

Thanks,

BigR