At position 2, the boats are still overlapped so B continues to have right of way under Rule 11. 2. No other rule of Part 2 applies. B does not break Rule 15 because she is about one and one-half hull lengths from A when she first acquires right of way at position 1. Although B has right of way under Rule 11, she is subject to Rule 17.1 and may not sail above a proper course while overlapped with A and within 2 hull lengths of her. Here B is sailing a proper course.
Several factors support that result.
Therefore, before B changes course to avoid A she is sailing a proper course and satisfying her obligations under Rule 17.1. Since at position 1 B has right of way under Rule 11 and is sailing a proper course, A is obligated under Rule 11 to keep clear of her, even if this means that A must change course to do so. In determining whether B is sailing a proper course, and thus whether A must keep clear of her, A's proper course is not relevant. B's proper course is one she would sail to finish as quickly as possible if A were not present. Before B changes course to avoid A, B is sailing at the same relative wind angle she has been sailing for the entire leg and thus is sailing a proper course.