I own two dinghies: The "travel dinghy", which is about 80 pounds and the bottom isn't painted (to be brought on deck). The "SUV dinghy" is 12 feet long, stays at the dock and is in the water full-time during the season. It weighs about 400 pounds including the 110 pound 4-stroke engine, battery, anchor and dual 3-gallon gas tanks. The picture below shows my automatic bilge pump setup. The check valve helps reduce cycling.