Section B – Boat on boat

RS CALL B4

Rule 17, On the Same Tack; Proper Course

Once a boat becomes overlapped within two of her hull lengths to leeward of a boat on the same tack, her obligation not to sail above her proper course while both boats remain on the same tack and overlapped continues even if the boats round a mark onto the next leg of the course.

Assumed Facts

BL, having rounded the windward mark clear astern of AW, establishes an overlap to leeward of AW at more than 4 hull lengths from the offset mark. AW gives BL markroom at the offset mark.

On reaching the offset mark, BL does not bear away towards the leeward mark but instead continues on a reach, above the course sailed by other boats in the heat. AW cannot bear away towards the leeward mark.

Question

Is BL required to bear away towards the leeward mark?

Answer

Yes.

BL, from clear astern, became overlapped within two of her hull lengths to leeward of AW on the same tack. Rule 17 applies and BL may not sail above her proper course. BL’s proper course is to bear away around the mark onto a course that she would sail to reach the leeward mark as soon as possible in the absence of AW.

BL was overlapped on the inside before either boat reached the zone at the offset mark. BL was entitled to mark room under rule 18.2(b). However, this does not modify her obligations under rule 17, which continues to apply during and after rounding this mark, whilst both BL and AW remain on the same tack and BL is overlapped within two hull lengths of AW. Unless BL has a compelling reason for continuing on a reach (for instance, to sail around a calm patch or weed), she sails above her proper course and breaks rule 17.

BL should take a penalty.