Question 1
Rule 19.1 applies between two boats “at” an obstruction. When are boats “at” an obstruction?

Answer 1
Boats are “at” an obstruction when the obstruction is influencing the course of one of them.

Question 2
Does the word “side” in Rules 19.1(a) and 19.2(a) refer to the side of the obstruction or the side of the boat?

Answer 2
In each of those rules, “side” refers to the side of the boat, either port or starboard.

Assumed Facts
Boat W is running on starboard tack parallel to a breakwater which is about one length away on her starboard side. Boat L is on starboard tack, to leeward and overlapped with W, and approaching the breakwater. Boats W and L are on a collision course.

Question 3 (Situation 1)
If L is broad reaching and approaching the obstruction as shown in the diagram for Situation 1, does rule 19 apply; and if so, which boat is the “outside boat?”

Answer 3
Because the wall is influencing W’s ability to keep clear of L, the boats are “at” the obstruction as that term is used in rule 19.1. Therefore, rule 19 applies.

Because L, the right-of-way boat under rule 11 (On the Same Tack, Overlapped), is choosing to pass the obstruction on her starboard side, a boat overlapped with her on her starboard side is an “inside boat.” Therefore, W is the “inside boat” and L is the “outside boat.”

Question 4 (Situation 2)
Does the answer to Question 3 change if L is close-hauled approaching the breakwater as shown in the diagram for Situation 2?

Answer 4
Yes. Because L, the right-of-way boat, is choosing to pass the obstruction on her port side (see rule 19.2(a)), a boat on her port side is an “inside boat” and a boat on her starboard side is an “outside boat.” Therefore, W is the outside boat and must give L room between her and the obstruction under Rule 19.2(b) as well as keep clear of her under Rule 11.

Question 5 (Situation 3)
Does the answer to Question 3 change if L is approaching the breakwater at a ninety degree angle to it?

Answer 5
Yes. Rule 19.2(a) gives L the right to choose to pass the breakwater on her port side or on her starboard side. No rule requires L to inform W of her choice. At the moment shown in the diagram, L’s course is directly at the obstruction (ninety degrees to it), and it is not possible to determine whether she is an “inside” and or an “outside boat” (see appeal ). Rule 19 applies, but while L continues on that course no part of Rule 19 creates any obligations on either boat. Rule 11 still applies and requires W to keep clear of l.

At some time after the moment shown in the diagram it will be necessary for L to either luff or bear away to avoid colliding with the breakwater. if L bears away, then the answer to this question is the same as Answer 3. If L luffs, then the answer to this question is the same as Answer 4.

January 2020