🚤 Water-Cooled ESC
A speed controller fitted with a cooling plate that lake water is pumped through while the boat runs.
The usual routing is pickup to ESC first, then on to the motor jacket, so the controller gets the coldest water.
What it actually does
Boat ESCs and motors are usually water cooled because there is no airflow inside a sealed hull. Water is picked up as the boat moves, pumped through a jacket around the motor and a plate on the ESC, and pushed back out — free cooling from the medium you are already travelling through.
In practice
The pickup is normally on the rudder or the transom, positioned to scoop moving water. The loop is simple silicone tubing, so the failure modes are simple too: a blocked pickup, a kinked tube, or a tube that has come off.
Worth knowing
Confirm water is actually flowing out of the outlet before every run — that visible stream is your only evidence the cooling loop is working. No stream means come back in immediately.