Regarding the new Cutter Rig definitions in the IRC Rule, when is a boat 'on a beat to windward'?
ISAF CASE 132
Rule 18.1(a), Mark-Room: When Rule 18 Applies
Rule 42.3(c), Propulsion: Exceptions
A boat is ‘on a beat to windward’ when the course she would sail to finish as soon as possible in the absence of all other boats is a close-hauled course or above.