In accordance with the definition Leeward and Windward, both boats are on starboard tack, therefore rule 11 applies as soon as they are overlapped and the blue boat (leeward) will have right of way at that time. At the moment when the overlap begins, Red must begin to keep clear and shall react to the luffing of the blue boat. Blue's course change to windward does not infringe rule 15 and rule 16. Rule 17 does not apply, because there is no proper course before the starting signal.