Rule 12 On the Same Tack, Not Overlapped Rule 18.2 Giving Mark-Room Rule 19.2 Giving Room at an Obstruction
Question 1
Three boats A, X and B, all on port tack, are approaching a gybe mark
directly astern of each other. A enters the zone clear ahead of X, and
then stops just inside the zone. B bears away onto a course to pass to
leeward of X. X then bears away to pass to leeward of A, and B and X become
overlapped. B bears away to avoid X and protests. What should the call
be?
Answer 1
No penalty.
A is an obstruction to X and B, first because they are both required to
keep clear of her under rule 12, and then because they are both required
to give her mark-room under rule 18.2(b). At position 1, X has right of
way over B and rule 19.2(a) allows her to choose which side to pass the
obstruction A. When X and B become overlapped, B must give room to X under
rule 19.2(b).
Question 2
If X and B are overlapped when X reaches the zone of the mark, how does
this limit the boats’ actions?
Answer 2
X and B are required to give A mark-room under rule 18.2(b). B must also
give X room to pass between her and A because A is an obstruction (see
answer 1 above).
When X enters the zone, she is overlapped outside B and rule 18.2(b) requires
her to give B mark-room, whether or not the overlap between them is subsequently
broken. If X has been unable to give mark-room from the time the overlap
began, she is not required to give mark-room, see rule 18.2(e). However,
if X is able to give B mark-room by slowing and then luffing astern of
A, rule 18.2(e) will not apply and, if X fails to do so, she will break
rule 18.2(b).
The presence of A may mean both X and B have to pass the wrong side of
the mark.
A boat racing is an obstruction for other boats if and only if they are required
to keep clear of her or give her room.