An amphibious vehicle power train has an engine with crankshaft and solid or fluid flywheel; a transmission arranged in line with the crankshaft, with an input shaft driven from the flywheel; and a power take off for driving shafts and marine propulsion means. The power take off has a driving sprocket attached to the crankshaft, a chain or belt, and a driven sprocket. Bevel gears are provided to convert transverse engine crankshaft rotation to longitudinal marine drive.