Rule 12, On the Same Tack, Not Overlapped Rule 19.2, Room to Pass an Obstruction: Giving Room
at an Obstruction
Definitions, Obstruction
If an obstruction can be passed on either side by two overlapped boats,
the right-of-way boat, if she chooses to pass it to leeward, must give room
to the other. If the right-of-way boat chooses to pass it to windward, she is
entitled to room to do so, and the other boat must keep clear. There is no obligation
to hail for room at an obstruction.
Assumed Facts
Boats BL and BW, overlapped on the starboard tack, are overtaking Boat
A, also on the starboard tack but moving more slowly. Rule 17 does not
apply between BW and BL during the incident.
Question 1
Does rule 19 apply between BW and BL as they overtake and begin to pass
A? If so, which parts of it apply and when do they apply?
Answer 1
At positions 1 and 2, rule 12 requires both BL and BW to keep clear of
A. Therefore, A is an obstruction to both BL and BW. However, A is not
a continuing obstruction, as the last sentence of the definition Obstruction
makes clear.
As BL and BW overtake A, BL may choose to pass A on either side (see rule
19.2(a)). When either BL or BW begins to pass A, provided that they are
still overlapped, rule 19.2(b) will apply. If BL chooses to pass A to
leeward, rule 19.2(b) will require her to give room to BW, as inside boat,
to do likewise if BW steers a course to do so. However, BW is not required
to take the room provided, and may pass A to windward, keeping clear of
her under rule 12 and then rule 11. If BL chooses to pass to windward
of A, then rule 19.2(b) requires BW to give BL room to pass A and rule
11 requires BW to keep clear of BL. Rule 12, and later rule 11, require
BL to keep clear of A.
Question 2
Does BW have to hail for room to pass to leeward of A? If not, would BL
risk disqualification by not giving room?
Answer 2
BW is not required to hail for room, although that is a prudent thing
to do to avoid misunderstandings. Rule 19.2(b) requires BL to give room
to BW if they both pass to leeward of the obstruction, whether or not
BW hails for room.