Does this also apply at a leeward Port rounding mark? You know the classic, spinnaker aproach on Starboard with a gybe drop.
Outside the 3-boat zone port has to give way to starboard. Once the first boat enters the zone and if there is an overlap then the inside boat has mark-room.
In practice, with a port-hand rounding, there is no difference. It is the same boat that has to give way, all the way. There is one small difference though. Outside the zone the starboard tack boat could hold her course to force the other boat to gybe, but inside the zone the inside boat that has to gybe around the mark, has to get on with it and not take any more room than she needs.
Strangely the rule (18.4) that says the inside gybing boat has to gybe and not delay, doesn't apply at a gate. I can't quite imagine yet why that would be the case.