The ornamental design for an equipmentring for a scuba harness, as shown and described.
FIG. 1 is a front perspective view of an equipment ring for a scuba harness embodying my new design attached to a scuba harness system, wherein the attached scuba harness system is shown in broken lines for illustrative purposes only and forms no part of the claimed design;
FIG. 2 is a rear elevational thereof;
FIG. 3 is a bottom view thereof;
FIG. 4 is a top view thereof;
FIG. 5 is a side view thereof, the opposite side being a mirror image thereof; and,