The definition Keep Clear states that a boat keeps clear if the right-of-way boat can sail 'her course’ with no need to take avoiding action. In the four situations below, B does not maneuver in an unseamanlike way and there is no contact.

Situation 1
A tacks onto starboard tack so close to B on port tack that A cannot sail straight ahead without hitting B, and B cannot avoid a collision by maneuvering promptly in a seamanlike way. A then immediately changes course to give B room to keep clear. A protests B under rule 10 and B protests A under rule 15.


Situation 2
B on port tack is clearly crossing A on starboard tack. A luffs so close to B that A cannot sail straight ahead without hitting B, and B cannot avoid a collision by maneuvering promptly in a seamanlike way. A then immediately changes course to give B room to keep clear. A protests B under rule 10 and B protests A under rule 16.1.


Situation 3
A establishes an overlap from clear astern on B. The overlap is so close to B that A cannot change course in both directions without making immediate contact with B. A then immediately changes course to give B room to keep clear. A protests B under rule 11 and B protests A under rule 15.


Situation 4
A and B are overlapped, with B as the windward boat. A luffs quickly, and before B can move away from A in a seamanlike way, the boats are so close that A cannot sail straight ahead without hitting B. A then immediately changes course to give B room to keep clear. A protests B under rule 11 and B protests A under rule 16.1.


Question
Is A sailing 'her course' as the term is used in the definition Keep Clear, when she changes course to fulfill her obligations under rules 15 and 16.1, such that B has kept clear and A has not broken rule 15 or 16.1?

Answer
A's course, ‘her course’ in the definition Keep Clear, is not her curved and changing course from position 2 to position 3 in the diagrams. It is a forward projection of the boat's position at any
given moment (allowing for current and leeway if relevant). The significant position in each diagram is position 2.

At Position 2 in each of the diagrams, A has herself created a situation where she needs to take the avoiding action referred to in (a) in the definition Keep Clear, because rule 15 or 16.1 required A to give B room to keep clear. A complied with those requirements by either bearing away or luffing.

Therefore, all protests by both A and B would be dismissed.

If A had not changed course to comply with rule 15 or rule 16.1, so that B was not able to keep clear, B would be exonerated under rule 64.1(a) for being compelled to break a rule of Section A.