Many older bilge pumps in cottage boats rely on a separate float switch to detect water in the hull. Often leaves and other debris lodge beneath the float: The switch stays on, the pump runs, and the battery drains. Conversely, corroded wiring or a faulty float can mean the pump never starts and the boat floods. Whale’s Supersub (about $120 for a model that pumps 1,100 US gallons per hour), one of a new generation of smart pumps, uses an integral electronic sensor that detects water pressure—no need for a separate float switch or its extra wires corroding in the bilge. The Supersub’s low profile makes it easy to install in tight spots, right at the lowest point of the bilge. A screened intake, which you can easily check and clean, protects the pump.
What about the tinnie? For small, uncovered boats with no battery, there are now several brands of self-contained solar-powered pumps (about $200), available at marine supply stores. These lightweight units look like a marine battery with a small solar panel on top and a discharge hose that goes over the transom. As long as you don’t cover the panel, the pump will protect your boat.