A BIG engine or electric motor.. Or a BIG sail.
it is very simple ,you just need a RC car and a toy boatfit the motor at the back of the boat and for steering get a servo and take two cardboard pieces attach them to the servo moving...
http://www.ehow.com/how_4779284_make-wooden-toy-boat.htmlhttp://www.ehow.com/how_6232094_make-toy-boat-out-wood.html
The earliest boats were log rafts. The first boats were hollow tree trunks propelled by poles, and then by paddles and oars.
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