For the past several issues I have been talking about tacking too close and most recently tacking too close at the mark. I am going to finish the series this month with one final situation. In this situation we see a boat trying to thread the needle between two other boats.
(click on the diagram to see a larger cleaner version)
In the diagram the green boat has overstood the weather mark and is approaching on starboard tack slightly below a close hauled course. The yellow and blue boats are approaching the mark on port tack with blue overlapped to windward when yellow gets to the three length zone. As we saw in November green does not have to give mark-room to blue and yellow, since green is on the opposite tack, and each of blue and yellow will have to tack to sail their proper course around the mark. (rule 18.1b) We saw in December that yellow has to give blue mark-room (rule 18.2b).
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,
18.2 Giving Mark-Room
(b) If boats are overlapped when the first of them reaches the zone, the outside boat at that moment shall thereafter give the inside boat mark-room. If a boat is clear ahead when she reaches the zone, the boat clear astern at that moment shall thereafter give her mark-room.
18.3 Tacking When Approaching a Mark
If two boats were approaching a mark on opposite tacks and one of them changes tack, and as a result is subject to rule 13 in the zone when the other is fetching the mark, rule 18.2 does not thereafter apply. The boat that changed tack
(a) shall not cause the other boat to sail above close-hauled to avoid her or prevent the other boat from passing the mark on the required side, and
(b) shall give mark-room if the other boat becomes overlapped
inside her.
Yellow and blue on port tack are approaching green on starboard tack, so both of them have to keep clear of green (rule 10). This makes green an obstruction to blue and yellow.
Obstruction
An object that a boat could not pass without changing course substantially, if she were sailing directly towards it and one of her hull lengths from it. An object that can be safely passed on only one side and an area so designated by the sailing instructions are also obstructions.However, a boat racing is not an obstruction to other boats unless they are required to keep clear of her, give her room or mark-room or, if rule 22 applies, avoid her. A vessel under way, including a boat racing, is never a continuing obstruction.
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.
20 ROOM TO TACK AT AN OBSTRUCTION
20.1 Hailing and Responding
When approaching an obstruction, a boat sailing close-hauled or above may hail for room to tack and avoid another boat on the same tack. After a boat hails,
(a) she shall give the hailed boat time to respond;
(b) the hailed boat shall respond either by tacking as soon as possible, or by immediately replying ‘You tack’ and then giving the hailing boat room to tack and avoid her; and
(c) when the hailed boat responds, the hailing boat shall tack as soon as possible.
Yellow is sailing close-hauled and she is approaching an obstruction. According to rule 20 she can hail for room to tack. She does this at position 2. Blue does not want to tack herself (since this would cause her to have to circle around to get back to the mark) and she is able to duck yellow so at position 3 blue complies with rule 20.1(b) by hailing “You Tack”. Yellow then tacks and rounds the mark.
Yellow was able to call for room to tack from blue and force blue to avoid her even though blue had earlier been entitled to mark-room since the preamble to Section C says “When rule 20 applies, rule 18 and 19 do not.”
Yellow tacks and completes her tack at position 5. Between position 5 and 6 green has to alter course to keep clear, but since this alteration was after yellow completed her tack, yellow did not break rule 13 or 15. Green has to alter course but only to a close-hauled course, not above it so yellow does not break rule 18.3.
Yellow has been very clever here and managed to use her requirement to keep clear of green as a way to force blue to go outside her. She has managed to tack in front of green without breaking rule 13, 15 or 18. On paper this is a great move. In practice I would suggest that it is a very risky one. It is quite likely that blue or green (or both) will protest her. Without a perfect replay of the incident as shown in the diagram it is quietly likely that a protest committee will decide one of the following:
a) After blue hailed "You Tack", yellow could have tacked before the mark and thusdid not tack "as soon as possible" thereby breaking rule 20.1(c).
b) Green had to alter course before yellow completed her tack and therefore yellow broke rule 13 or 15.
c) Green had to alter course above close-hauled to avoid yellow so yellow broke rule 18.3.
Sometimes manoeuvres that appear legal on paper should be avoided on the water. I think the sailor in yellow has been spending too much time reading my articles.
© Copyright 2011 Andrew Alberti