We claim an ornamental design for a surfboard leash, as shown and described.
FIG. 1 is a perspective view of a surfboard leash, showing our new design;
FIG. 2 is a right-side view thereof;
FIG. 3 is a left-side view thereof;
FIG. 4 is a front view thereof;
FIG. 5 is a rear view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is a perspective view thereof; and,
FIG. 9 is a perspective view of a surfboard leash in association with a surfboard.
The dashed lines are included for illustrating environmental structure and form no part of the claimed design. The surfboard leash is shown broken away to show indeterminate length and for ease of illustration.