An apparatus comprises a rectangular fitting dimensionally conformed to a perimeter of a bathtub wall. The rectangular fitting includes a first portion and a middle portion. The first portion comprises a water-impermeable material coated with an adhesive material along the length of a bottom surface. The first portion includes a top surface conjoined with the middle portion. The adhesive-coated bottom surface of the first portion securely adheres to a top surface of the bathtub wall in order to be dimensionally conformed to the perimeter of the bathtub wall. The middle portion is configured to extend upward and downward to pre-determined heights by a user while the first portion securely adheres to the bathtub wall. The apparatus is configured to store water above the top edge of the bathtub wall, thereby converting the bathtub into the soaker.