Blue, the windward boat, must keep clear in accordance with rule 11 and definition Keep Clear. Red, the leeward boat, must be able to change her course in both directions without immediately making contact with the windward boat. The gybe, a necessary result of Red's bearing away, immediately causes contact between the two mainsails and does not change the right of way (only the rule changes from rule 11 to rule 10). Therefore Blue infringed rule 11 and rule 10 and will be penalized. (Even if the gybe is not necessary for bearing away, Red is right of way boat before and after the gybe and the blue boat has to keep clear all the time and there is no rule that prohibits Red from gybing without changing course.) Red's action is within the rules, but will not win Red many friends among his fellow competitors. Rule 15 is not applicable.