The Quadski — a one-person all-terrain vehicle that doubles as a personal watercraft — is being billed by its makers as the first high-speed, commercially available amphibious vehicle. It's scheduled to go on sale in the U.S. by the end of this year for around $40,000. Michigan-based Gibbs Sports Amphibians Inc. hopes to sell the vehicle worldwide by 2014.

With its all-terrain tires and four-cylinder, BMW-supplied engine, the Quadski can drive up to 45 miles per hour on land. To take it into the water, the driver presses a button. In five seconds, the four wheels fold up and tuck into the sides.