Section B - The Prestart
MR CALL B16
Rule 10, On Opposite Tacks
Rule 19.2(b), Giving Room at an Obstruction
Rule 43.1(b), Exoneration (room or mark-room)
Definitions, Clear Astern and Clear Ahead; Overlap
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.
Flag Y is displayed. 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 by rule 43.1(b).
Question 2
Blue is sailing a course that is more than ninety degrees from the true wind 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. Flag
Y is displayed. What should the call be?
Answer 2
Penalize Blue.
The definition Clear Astern and Clear Ahead; 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.