Question 1
Yellow on starboard tack and Blue on port tack, both close-hauled, are approaching the windward mark. Blue bears away and passes astern of Yellow. Yellow luffs slowly and nearly stops head to wind with the mark abeam. While Yellow is luffing Blue tacks to starboard and bears away towards the mark. Yellow does not give room at the mark, and Blue luffs to avoid a collision.
There is a Y-flag from Blue. What should the call be?

Answer 1
The boats enter the two-length zone on opposite tacks on a beat to windward. Therefore, rule 18 does not apply. When Blue has passed head-to-wind, the boats are overlapped on the same tack and are both about to round the mark. Therefore, rule 18 applies. There was neither an overlap nor were they clear ahead/clear astern when the first of the two boats entered the two-length zone.
Rule 18.2(a) applies and this requires Yellow to give Blue as an inside boat room to round the mark.
If Yellow is unable to give room in time for Blue to round inside her, rule 18.2(e) applies. Display the green and white flag.
If Yellow is able to give room in time for Blue to round inside her, rule 18.2(a) applies. Yellow fails to give this room. Penalize Yellow.