A bathtub whirlpool toy and educational device has a bottom and gasket designed to allow the device to fit over the drain of a household fixture such as a bathtub or sink. The device has a generally cylindrical interior space having inlet slots set at an angle, so that water entering the interior from the bath will begin to rotate immediately. A central outlet leads to a recuperation chamber having an offset recuperation chamber outlet allowing the recuperation chamber outlet to sit directly over a bathtub drain. The recuperation chamber may have a plurality of vanes/fins designed to reduce water circulation and increase water flow. An adapter may allow the user to alter the size and shape of the interior space outlet aperture, and may be fixable in place or movable during use so as to allow the user to alter the vortex/whirlpool dynamically.