Section B – Boat on boat

RS CALL B9

Definitions, Mark-Room
Rule 13, While Tacking
Rule 18.1, When Rule 18 Applies
Rule 18.2, Giving Mark Room
Rule 43.1(b), Exoneration

When a boat is entitled to mark-room, room for her to sail her course at the mark does not include room to tack unless she is overlapped to windward and on the inside of the other boat and sailing within the mark-room to which she is entitled. This applies whether or not the boats were overlapped at the zone.

If contact occurs when a windward inside boat tacks at the mark, that contact may be evidence that the outside boat failed to give the inside boat the room that she needed to tack.

Assumed Facts 1

IW and OL, are overlapped on port tack when they enter the zone of a windward mark that is to be rounded to port. Both boats are close-hauled and IW, windward boat, is keeping clear. As IW luffs to tack, her stern swings outwards and, after she passes head to wind, there is contact between the two boats. There is no damage. OL protests.

Question 1

Which rule, if any, has been broken?

Answer 1

From the time one of the boats enters the zone, rule 18 applies and OL is required by rule 18.2(b) to give IW mark-room. Because IW is overlapped to windward and on the inside of OL, and she would be fetching the mark after the tack, mark-room includes room to tack.

Although rule 18 ceases to apply after IW passes head to wind, because the boats are now on opposite tacks on a beat, the subsequent contact shows that before IW passed head to wind, OL had failed to give her mark-room. OL broke rule 18.2(b) and should take a penalty.

IW, after passing head to wind, failed to keep clear of OL. IW broke rule 13, a rule of Section A of Part 2, but is exonerated under rule 43.1(b).

Assumed Facts 2

The situation is the same except that the contact happens after both boats have passed head to wind, and before either boat reaches a close-hauled course.

Answer 2

When one boat passes head to wind, IW and OL are on opposite tacks on a beat to windward and rule 18 ceases to apply. As soon as both boats have passed head to wind, they are overlapped on starboard tack and rule 18.2(a) requires OL to give IW mark-room, which includes room to round the mark as necessary to sail the course.

OL does not give IW mark-room and so breaks rule 18.2(a). OL should take a penalty. Until IW reaches a close-hauled course, she is breaking rule 13. However, she is sailing within the mark-room to which she is entitled and is exonerated under rule 43.1(b). Thereafter she becomes a leeward right-of-way boat.