Forget remote controlled and Mr. T rubber duckies. Actually, forget rubber ducks altogether. What I want is some bubble bath and this DIY bathtub steam boat. Yes, it's a real, functional, bathtub-sized steamboat. And yes, it's complete with putt-putt sounds.
Just like a real steam boat, this six-inch version moves because of expanding steam pushing away from water. Mimicking the real thing further, there's a compact boiler and motor made of copper pipes and even a heat shield. You get things started by lighting a small "lamp" filled with olive oil and watching the steam come out before the boat zips across the bathtub.
The instructions provide the in depth details on the physics and go step-by-step from cutting and building the hull to putting together the boiler. All that's missing is a guide on how to whistle like Mickey Mouse. [Duckworks via Make]