CASE 76

Rule 16.1, Changing Course
Rule 18.1(b), Rounding and Passing Marks and Obstructions: When This Rule Applies

When a boat changes course to a new proper course, this may break rule 16.

Question
S on starboard tack and P on port tack were on a leg from the leeward mark to the finishing line. S has overstood and bears away to clear the stern of the committee boat at the starboard end of the line. P can cross S clear ahead if S maintains that course, and P hails S to hold her course. As she passes the stern of the committee boat, her proper course becomes a close-hauled course. S comes up to a close-hauled course at which point there is less than a hull length between S and P. Both then go head to wind, and they manage to avoid contact by the narrowest of margins. What rules govern the relationship between the two boats?

Answer
S is not entitled to room from P under rule 18.2(a) because, as stated in rule 18.1(b), the boats are on opposite tacks on a beat to windward, and so rule 18 does not apply. P is subject to rule 10 which requires her to keep clear of S, but S is subject to rule 16.1 which prohibits her from changing course without giving P room to keep clear, even when S is changing to a new proper course. In this situation when S changed course just after passing the stern of the committee boat, she did not give P enough room to keep clear and, therefore, broke rule 16.1.

144
S is not entitled to room from P under rule 18.2(a) because, as stated in rule 18.1(b), the boats are on opposite tacks on a beat to windward, and so rule 18 does not apply. P is subject to rule 10, which requires her to keep clear of S, but S is subject to rule 16.1, which prohibits her from changing course without giving P room to keep clear, even when S is changing to a new proper course. In this situation when S changed course just after passing the stern of the committee boat, she did not give P enough room to keep clear and, therefore, broke rule 16.1. P broke rule 10, but was compelled to do so because S broke rule 16.1, and so is to be exonerated under rule 64.1(b)

USSA 1980/231