FIG. 1 is a top, front, right side perspective view of a double basin sink showing my new design;
FIG. 2 is a top, rear, left side perspective view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a front elevation view thereof;
FIG. 6 is a rear elevation view thereof;
FIG. 7 is a right side elevation view thereof; and,
FIG. 8 is a left side elevation view thereof.
The broken lines shown in the figures represent portions of the double basin sink that form no part of the claimed design.