Here is a quick post on my bilge pump system. This is a little pump I got from Amazon and a little rig that plugs into the AUX on your RX so you can turn it on and off from your TX assuming you have at least 3 channels. I did not mess with an auto system. I simply hit the AUX on the transmitter to check for water. It works very well. I poured about 12 oz of water in the hull and the pump evacuated it in about 30 seconds. This particular pump does not need to be submerged. It is a diaphragm pump so it will suck from well above the water. I mounted it under the ESC tray and ran a rigid tube to the back of the hull. Then a short dump overboard.
AUX on/off switch.
Pump.
