Abstract: A mounting bracket system for a rearview mirror intended to be temporarily and readily affixed to a protruding surface of a watercraft or a vehicle. The instant invention finds particular advantage when a load is being towed or trailed and the normal rear line of sight is obscured. The mounting bracket of the instant invention is adapted to receive a conventional mirror assembly on one end, the other end terminates in a generally orthogonal, cylindrical appendage. The appendage is selectively oriented and contacted between two opposing clamping members. The first clamping member is affixed to a frame adapted to engage the protruding surface. The second clamping member is slidably displaceable relative to the first clamping member.