The first four rules in Part 2 of the Racing Rules of Sailing (rules 10, 11, 12, and 13) establish which boat must keep clear when two boats meet. The next few rules (Rule 15, 16, and 17) put limits on the right-of-way boats. With this article we will start rule 15, which applies. Rule 15 applies when the right-of-way changes.

In the first diagram, Blue and Yellow are sailing on a reaching leg. At position 1, Blue is clear astern of Yellow. Rule 12 says that Blue shall keep clear of Yellow. At position 2, Blue gets an overlap to leeward of Yellow. Blue is now the leeward boat and Yellow must keep clear.  Yellow immediately alters course to try to keep clear, but her stern touches Blue. Blue has just become the right-of-way boat, so rule 15 applies. Blue has to initially give Yellow room to keep clear. Yellow did not have room, so Blue broke rule 15. If Yellow had waited a while, then the “initially” in rule 15 would have run out and Yellow would have broken rule 11. There is no clear definition of “initially,” since it depends upon the conditions, but it is a short time – the time needed for the other boat to react.


We looked at another common situation when rule 15 applies a few months ago. In positions 1 and 2, Red is on port tack and Green is on starboard tack, so Red has to keep clear. From position 3 to position 4, Red is a tacking boat, so she still has to keep clear. At position 5, when Red gets to a close-hauled course, she has completed her tack. Red is clear ahead of Green, so Green has to keep clear. Initially under rule 15, Red has to give Green room to keep clear.



The next diagram illustrates the other part of the rule. Orange is clear ahead of white and to leeward. White has to keep clear of Orange.  From position 4 to position 5, Orange tacks in front of White onto port tack. White is now the right-of-way boat. Since White became the right-of-way boat because of Orange’s actions, White does not have to initially give Orange room to keep clear.
 

Room The space a boat needs in the existing conditions, including space to comply with her obligations under the rules of Part 2 and rule 31, while manoeuvring promptly in a seamanlike way.
10 ON OPPOSITE TACKS
When boats are on opposite tacks, a port-tack boat shall keep clear of a starboard-tack boat.
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.
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.
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.
15 ACQUIRING RIGHT OF WAY
When a boat acquires right of way, she shall initially give the other boat room to keep clear, unless she acquires right of way because of the other boat’s actions.
 
Copies of these rules articles along with animated diagrams can be found at www.rcyc.ca > sailing > racing > know your rules.