Sit-up bathtub
FIG. 1 is a front prospective view of a sit-up  bathtub showing our new design. 
     FIG. 2 is a top plane view thereof. 
     FIG. 3 is a cross-sectional view taken on line 3--3 of  FIG. 2. 
     FIG. 4 is a cross-sectional view taken on line 4--4 of  FIG. 2.