At the moment that Green reaches the zone, Red is clear astern. Therefore rule
18.2(b,c) applies and Red must thereafter give mark-room.
(Until the boats have passed the mark.) If Red holds this course, she will not
give mark-room.
Remark: When Blue reaches the
zone she is overlapped with Red and rule
18.2(b) applies. Therefore Blue shall give Red and Green, the inside boats
mark-room.