After sailing alongside P for some time on port tack, S gybes to starboard tack without breaking rule 15. Both boats continue to sail parallel courses. About two minutes after her gybe S begins to luff. P does not respond to the luff and the boats touch at position 3. There is no damage or injury.

At the time of the contact, does rule 15 still apply? Does S break rule 16.1?

S as the starboard-tack boat has right of way under rule 10, and P as the port-tack boat must keep clear. Rule 15 applies only briefly after S becomes the right-of-way boat, but rule 16.1 continues to limit how S may change course. S may luff provided that she does so in a way that gives P room to keep clear, and P must be prepared to react promptly, if necessary by gybing, to continue to keep clear.  Since P has room to keep clear of S by responding promptly when S luffs, S does not break rule 16.1. P does not keep clear and does not avoid contact with S. P therefore is to be penalized for breaking rules 10 and 14(a).

S also breaks rule 14 because, after it became clear that P was not keeping clear, S could have avoided the contact. However, because there was no damage or injury she is exonerated by rule 43.1(c).

DEN 2005