PURPOSE: A model testing tub is provided to have functions of an inner harbor maneuvering tub and a marine tub, thereby improving productivity by the reduction of manufacturing costs. CONSTITUTION: A model testing tub includes a water storage unit. The water storage unit includes a first storage unit (21) having first water level on a predetermined portion in the longitudinal direction; and a second water storage unit (22) having second water level on a predetermined portion in the longitudinal direction. A water level regulating plate (30) is arranged in the second water storage unit to vary the second water level so that the water storage unit can be utilized as either an inner harbor maneuvering tub or a marine tub.
