Abstract: A planing amphibious vehicle with retractable wheels and a sit-astride seat having dimensions that impart enhanced capability in both land as well as water modes of operation. The beam, track, dead rise angle and the location of the handlebars cooperate to enhance freeboard and ground clearance without sacrificing manoeuvrability. The length is at least 2400 mm; the beam is at least 1250 mm; the deadrise angle at least 10°; and the handlebars are located only slightly forward of the halfway distance from transom to bow.

Abstract: Amphibious vehicle needs less power on land than on water. A control system is provided to limit power and/or speed on land, using: restriction of flow of fuel, air, or exhaust gases; heated intake air; exhaust gas recirculation; declutching of a supercharger; bypassing of a turbocharger; a variable throttle stop, dual throttles, or a switchable throttle damper; cylinder or intake valve deactivation; a dual length intake manifold; dual mode ignition or engine mapping; dual fuel—gasoline on water, compressed natural gas on road; variable compression ratios or valve timing; a clutch designed to slip; automatic brake application; or aerodynamic brakes. The suspension may tilt the vehicle to increase aerodynamic resistance. The road transmission may be geared to limit maximum speed. High rolling resistance tires or twin engines may be used. A sensor on retractable suspension may indicate whether the vehicle is on land or on water.