The outside right-of-way boat is obligated by 19.2(b) to give room to the inside boat at an obstruction but does not need to take avoiding action until the moment she needs to change course to fulfil her obligation under rule 19.2(b).
Question 1
Yellow and Blue are both sailing more than ninety degrees from the true wind. Blue, on port tack is sailing along a continuing obstruction. Yellow, on starboard tack is approaching the obstruction on a collision course with Blue. Yellow bears away and avoids Blue. There is a Y-flag. What should the call be?
Answer 1
Display the green and white flag. Both boats are sailing more than ninety degrees from the true wind and are overlapped. Yellow is the outside boat and is required by rule 19.2(b) to give Blue room between her and the obstruction. By bearing away to give room between positions 3 and 4 Yellow fulfilled her obligation under rule 19.2(b).
At position 3 Yellow needed to take avoiding action; therefore Blue was not keeping clear under rule 10. However Blue was sailing within the room to which she was entitled under rule 19.2(b) and is therefore exonerated under rule 21.
Question 2
Blue is sailing downwind on port tack along a continuing obstruction. Yellow is sailing an upwind course on starboard tack and is approaching the obstruction on a collision course with Blue. When it is obvious that Blue is not going to change course, Yellow luffs and avoids Blue.
There is a Y-flag. What should the call be?
Answer 2
Penalize Blue.
The definition Overlap only applies between boats on opposite tacks when both are sailing more than ninety degrees from the true wind. Since Yellow is not sailing at more than ninety degrees from the wind, the boats are not overlapped and rule 19.2(b) does not apply. Yellow does not have to give room to Blue. When Yellow has to luff, Blue does not keep clear and breaks rule 10.