Remember, they were on opposite tacks so starboard/port takes precedence. You're thinking windward/leeward if they were both sailing on the same tack.

In this case, if the I-20 had immediately jibed to port after the A-rounding and been on a collision course with the H-16 still going upwind on port tack, the H-16 would have been the right of way boat.

Bob Hodges