Rule 10 and rule 18?
Situation: Two Beetlecats approaching the leeward mark, both running by the lee. The mark will be taken to port. Inside the zone, boat A is on port tack and is the inside boat with an overlap on boat B. Boat B is on starboard tack. Boat B (outside boat) calls "Starboard!" and bumps into boat A; B's port rail hits A's starboard rail, a light tap/rub, no damage, no change of course by either boat.
Question: Which rule 'trumps'? Rule 10 says boat B (outside boat) has rights because B is on starboard. Rule 18 says boat A (inside overlapped boat) must be given mark room. As I understand from reading the rules, rule 18 applies because there is an overlap in the zone and therefore the outside boat must give the inside boat mark room.
I've attached a drawing, there's actually a third boat (boat C) inside of both A and B.
Thanks for helping a newbie racer trying to understand the rules! I'd be glad to provide any other useful information.