Boat superstructure
FIG. 1 is a side elevational view of a boat superstructure showing my new design, the left side elevational view being a mirror image of that shown; 
     FIG. 2 is a top plan view thereof; 
     FIG. 3 is a front elevational view thereof; and, 
     FIG. 4 is a rear elevational view thereof. 
     The broken lines shown in FIGS. 1, 3 and 4 are for illustrative purposes only and form no part of the claimed design.