Last month I discussed the situation at a leeward mark where a starboard-tack boat has to give room to a port-tack boat. Before I continue with situations where starboard tack has to give way to port tack, I want to show two situations that may seem similar to last month but which are not. In last month’s situation, starboard had to give “mark-room” to port according to rule 18.2. Rule 18.1 describes when rule 18 applies and more importantly where it does not.
SECTION C
AT MARKS AND OBSTRUCTIONS
Section C rules do not apply at a starting mark surrounded by navigable water or at its anchor line from the time boats are approaching them to start until they have passed them. When rule 20 applies, rules 18 and 19 do not.
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.
(click on the diagram to see a larger cleaner version)
In the diagram we have the red boat on port tack approaching a weather mark. Green is approaching on starboard tack. They are therefore on opposite tacks on a beat to windward and the proper course for the red boat, but not the green boat, will be to tack to round the mark, so rule 18.1a and 18.1b both say that rule 18 does not apply. This means that the green boat will not have to give mark-room to the red boat and as the port-tack boat, red will still have to keep clear (just as if the mark was not there).
The second situation is closer to the leeward mark I showed last month. It is also much less common. I did however see it happen in two Friday night TGIF races this spring.
(click on the diagram to see a larger cleaner version)
The start was downwind. The blue boat was coming into the committee boat on port tack. The yellow and white boats were approaching on starboard tack. The preamble to section C says that the rules of section C do not apply at a starting mark surrounded by navigable water … from the time the boats are approaching to start”. Since they are all “approaching the starting line to start” rule 18 does not apply. Blue has got herself into hot water here. She is not entitled to mark-room and as port-tack boat should be keeping clear according to rule 10 (opposite tacks). We don’t see this situation very much since we don’t see downwind starts very often. This situation is very similar to barging on a normal upwind start. There again, rule 18 does not apply, so the rules of part A rule 11 (same tack overlapped) do apply.
© Copyright 2011 Andrew Alberti