The problem with autobailers (aptly named by some wags as autosinkers) is that they only work when the boat is moving and sometimes get debri stuck in them holding them open rendering them useless if you stall or stop moving. If you run a clutch and sit still , water will still come in stuffing tube and eventually sink boat if you don't move from time to time.

Check out what the guys with the battling warships use. some build what is known as a penny pump.As the name implies its built using a penny with impellers soldered onto it and put in a housing. driven with a small motor it will pump water with little weight penalty.