Question 1
Yellow and Blue in one match and Green in another match are approaching the windward mark overlapped. The mark is to be rounded to starboard

When Green enters the zone, she is overlapped with Yellow and Blue, who are overlapped on port tack. Yellow and Blue are on a collision course with Green.

Blue does not hail for room to tack. At position 3, Blue bears away and passes close behind Green. Yellow luffs and tacks to avoid Green and Y-flags.

What should the call be?

Answer 1
Green is an inside overlapped boat and therefore entitled to mark-room from Blue and Yellow under rule 18.2(a)(1) (rule C2.9). Blue is an inside overlapped boat relative to Yellow and therefore entitled to mark-room from Yellow under rule 18.2(a)(1) (rule C2.9).

If Yellow gave Blue room to tack but Blue did not tack, display the green and white flag. Yellow has given mark-room to both Blue and Green and Blue has given mark-room to Green. Note that rule 19 does not apply (see rule 19.1(b)).

If Yellow did not give Blue room to tack as part of Blue’s proper course, and/or Blue’s obligation to give Green mark-room, penalise Yellow. Blue does not need to hail nor make arm signals for 'room to tack' as the room required to be given by Yellow is mark-room as required by rule 18, not room as required by rule 20.

Question 2
The situation is the same as in Question 1, but instead of luffing and tacking, Yellow bears away with Blue to pass behind Green and there is contact between Yellow and Green. Blue displays a Y-flag. What should the call be?

Answer 2
Penalize Yellow.

Rule 19 does not apply, therefore Blue is not required to give Yellow room to pass between Green and herself. Yellow fails to keep clear of (and give mark-room to) both Green and Blue under rules 10, 11, and 18.2(a)(1).