Originally Posted by JeffS
... if boats are coming from two different directions to the same mark there is no visible overlap but one boat will be in the 3 boat length zone first, that boat then has all the rights ...

That is not correct. The scenerio in question has catamarans sailing hot downwind on opposite tacks towards the same mark. If two boats are sailing 30-45 degrees off the true wind on oppposite tacks, then they are most likely overlapped. In that case, when they reach the zone, the outside boat must thereafter give the inside boat "mark-room" under RRS 18.2(b). It is not a matter of "the first boat has all the rights".

Regards,
Eric