I am going to take break from rule changes and cover a situation based on a question I was sent recently.
(click on the diagram to see a larger cleaner version)
In the diagram, Blue and Yellow are sailing downwind. They are both on starboard tack. Yellow is on a reach aiming for the gate mark. Blue, whose fleet started earlier and is therefore a lap ahead, is aiming for the finishing line. Blue does not have to go through the gate since it is not a mark of the course on the last downwind leg. Blue feels that she is not being given room to finish by Yellow. She is not being allowed to sail her proper course.
18 MARK-ROOM
18.1 When Rule 18 Applies
Rule 18 applies between boats when they are required to leave a mark on the same side and at least one of them is in the zone.
However, it does not apply
(a) between boats on opposite tacks on a beat to windward,
(b) between boats on opposite tacks when the proper course at the mark for one but not both of them is to tack,
(c) between a boat approaching a mark and one leaving it, or
(d) if the mark is a continuing obstruction, in which case rule 19 applies.
Rule 18, covers all marks other than a starting mark surrounded by navigable water, so room to finish and room at a mark are covered by it. Rule 18.1 defines when the rest of rule 18 applies. These two boats are not required to leave the same mark on the same side so the rest of rule 18 does not apply. As far as room to finish, this would also only apply when both boats got to the three-length zone of the finishing mark, which neither is at this point,
Blue also feels that she is not being allowed to sail her proper course. There are no rules that force Yellow to allow Blue to sail her proper course. Yellow is the leeward boat, making her the right-of-way boat (rule 11). She may or may not be allowed to sail above her own proper course depending upon how she established the overlap (rule 17). This doesn’t really matter though since her proper course is probably towards the mark that she is sailing around and this is the course that is causing problems for Blue. Yellow is allowed to sail that course.
At position 6, Yellow heads up quite significantly and quite quickly. She does it in a way that makes it almost impossible for Blue to keep clear. When she does this, she breaks rule 16. This is where the fact that mark-room does not apply starts to hurt Yellow instead of Blue. Normally boats are allowed to alter course quickly while rounding marks. If a boat is entitled to mark-room, then she is exonerated if she breaks rule 16 in an incident with a boat required to give her mark-room. Since rule 18 does not apply, neither boat is entitled to mark-room so Yellow is not exonerated for breaking rule 16.
16 CHANGING COURSE
16.1 When a right-of-way boat changes course, she shall give the other boat room to keep clear.
21 EXONERATION
When a boat is sailing within the room or mark-room to which she is entitled under a rule of Section C, she shall be exonerated if, in an incident with a boat required to give her that room or mark-room,
(a) she breaks a rule of Section A, rule 15 or rule 16, or
(b) she is compelled to break rule 31.
Situations like this require some anticipation on the race course. Blue might be better to plan a course that keeps her away from boats rounding the gate marks. Either boat might find it better to take the other’s stern. A little communication and a little co-operation can probably avoid the problems in this situation
© Copyright 2013 Andrew Alberti