18.3 Tacking in the Zone

If a boat passes head to wind from port to starboard tack in the zone of a mark to be left to port, rule 18.2 does not apply between her and another boat on starboard tack that is then fetching the mark. If the other
boat has been on starboard tack since entering the zone, the boat that passed head to wind
(a) shall not cause the other boat to sail above close-hauled to avoid contact, and
(b) shall give mark-room if the other boat becomes overlapped inside her.