A tactical transport cart manually navigable by a single human operator over both topographic and hydrographic terrains has a frame, a payload-supporting area on the frame, a pair of wheels or other terrain-engaging transport propulsion members attached to the frame, a handle structure attached to the frame, at least one motor connected in driving relation to the transport propulsion members, a battery for providing motive power to the motor, and a control device connected between the battery and the motor for controlling supply of motive power to the motor, with a switch device mounted on the handle structure for selective actuation and deactuation of the motor. The frame, transport propulsion members and handle structure are cooperatively dimensioned and configured for movement of the cart over ground surfaces of topographic terrains and for partially and fully submerged movement over water-covered surfaces of hydrographic terrains.