Last week inside the mess hall of the USS Turner Joy, third-grader Madalyn McGraw and her friends from Gateway Christian Schools watched a tiny tin boat with a small candle inside putter across a tub of water. "The heat makes steam and the steam makes it move," Madalyn explained, quickly catching on to the engineering of the small craft, which had a tiny tailpipe to draw in water for the steam. "It's cool how the energy moves the boats," she said. "I love science." That's the reaction folks from the nonprofit Bremerton Historic Ships Association want in students they bring aboard for tours of the decommissioned Vietnam-era destroyer Turner Joy, a floating museum on Bremerton's waterfront.