It's powered by a rubber band! Just like the old traditional paddle boat toys, this one too will flap its paddle wheel in the water when you twist up the rubber band and let her go. Super easy to build, but lots of fun for kids of any age. Stain or paint as you like. Full size patterns for all, plus some written instructions. Finished size of the boat is: 8" long, by 3" wide, by 6" tall.