I spent some time with a high level racing team (no names) recently doing some training. I was surprised by some basic errors in rules knowledge that at least some members of their team had. When I learned the very basic right-of-way rules I was taught that the overtaking boat must keep clear. This may apply for power boats. In sailing it is a very simplified version of this rule and often does not apply. The sailing rule is rule 12.
12 ON THE SAME TACK, NOT OVERLAPPED
When boats are on the same tack and not overlapped, a boat clear astern shall keep clear of a boat clear ahead.
The second part of the rule is very similar to the simplified version “a boat clear astern shall keep clear of a boat clear ahead”. The first part of the rule puts two restrictions on it is applicability. The boats have to be on the same tack and they cannot be overlapped.
(click on the diagram to see a larger cleaner version)
In the diagram, the green on starboard tack boat is clear astern of the red port tack boat. She is “overtaking”. They are not on the same tack so rule 12 does not apply. Rule 10 applies and the port tack boat has to keep clear of the starboard tack boat.
10 ON OPPOSITE TACKS
When boats are on opposite tacks, a port-tack boat shall keep clear of a starboard-tack boat.
(click on the diagram to see a larger cleaner version)
In the second diagram, the two boats are on the same tack. The blue boat is very slowly overtaking the yellow boat. At position 1 they are already overlapped since the spinnaker of blue is over the stern of yellow. Since they are overlapped rule 12 does not apply. Blue is the leeward boat and yellow must keep clear under rule 11.
Clear Astern and Clear Ahead; Overlap
One boat is clear astern of another when her hull and equipment in normal position are behind a line abeam from the aftermost point of the other boat’s hull and equipment in normal position. The other boat is clear ahead. They overlap when neither is clear astern.…
11 ON THE SAME TACK, OVERLAPPED
When boats are on the same tack and overlapped, a windward boat shall keep clear of a leeward boat.
The final situation is less common. This particular scenario took place before the start in a match race. It could take place in a fleet race and the rules are the same.
(click on the diagram to see a larger cleaner version)
The orange boat and the purple boat have been sailing along on the same tack. Orange is clear ahead so purple has to keep clear. Orange luffs up and purple still has to keep clear. At position 4 orange has crossed head to wind. She is now changing tacks and subject to rule 13. She has to keep clear while purple comes up behind her. They are not on the same tack so rule 12 does not apply. Rule 13 also makes it clear that rule 12 does not apply.
13 WHILE TACKING
After a boat passes head to wind, she shall keep clear of other boats until she is on a close-hauled course. During that time rules 10, 11 and 12 do not apply. If two boats are subject to this rule at the same time, the one on the other’s port side or the one astern shall keep clear.
© Copyright 2012 Andrew Alberti