The ornamental design for a dimpleplug for a surfcraft, as shown and described.
FIG. 1 is a top perspective view of a dimple plug for a surfcraft of the present invention;
FIG. 2 is top plan view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a front elevational view thereof, the back elevational, the left side elevational and the right side elevational views each being a mirror image thereof; and,
FIG. 5 is a cross sectional view taken along the line and in the direction of arrows 5-5 of FIG. 2.