Both Red and Blue will be penalized. Blue becomes overlapped from clear astern and remains overlapped within two hull-lengths. Therefore Blue remains subject to rule 17 and must not sail above her proper course. It will be hard to believe any claim by Blue that her new course is her proper course. Otherwise she would have sailed this course before she established this leeward overlap. Therefore Blue infringes rule 17 and will be penalized. However, Red is obliged by rule 11 to try to keep clear of the leeward boat, even one that is breaking a rule. Here, Red takes no avoiding action at all and will also be penalized for infringing rule 11, Red cannot be exonerated from this infringement under rule 64.1(a) because she was not compelled to break rule 11 by Blue's infringement.