boat motor question?

hi im wondering if i am able to start my boat during the lakedrawdown this winter. the boat is a pontoon sittin on boards on my dock, water level only dropped 3 feet this year so motor is part way in the water. well i started it and water comes peeing out the back so does it mean the water cool feature is working on the motor and i shouldnt worry about starting it and letting it warm up ?? thanks all