This boat is called the SolarShuttle, and guess what? It runs on solar power, not filling the air with exhaust from a gas-powered engine like most boats. It's pretty efficient, too, toting up to 42 passengers silently around the surface of the water. It even stores energy, allowing travel at night when the sun isn't out, and is able to send extra juice back to national utility plants.
It would be nice to see this technology make it into more ships, as nothing ruins the serenity of a calm lake like a blaring engine and a plume of exhaust. With solar-powered boats, hanging out by or on the lake would be better for everyone.