A method of navigating an UAV over water with vertical takeoff and landing (VTOL) function. The UAV having a plurality of lift propellers; a cabin engaged with a plurality of lift propellers; a water propulsion system engaged with the cabin to push the cabin in a forward direction when the cabin is at least partially immersed in water; at least one water inlet engaged with the water propulsion system; the cabin is a cargo hold or a passenger cabin. The UAV provided by the disclosure can realize vertical takeoff and landing in the water area, and fly, drive and navigate freely in the whole area.