28  Sailing the Course
28.1 A boat shall start, pass each mark on the required side in the correct order, and finish, so that a string representing her wake after starting and until finishing would, when drawn taut, lie on the required side of each mark and touch each rounding mark. She may correct any errors to comply with this rule. After finishing, a boat need not cross the finishing line completely.
(2001) CYA prescribes that, in the absence of the race committee, a boat shall take her own finishing time and report it to the race committee as soon as possible. If there is no longer an established finishing line, it shall be a line extending from the required side of the finishing mark at right angles to the course from the last mark and of the shortest practicable length.

28.2  A mark has a required side for a boat only when she is on a leg that the mark begins, bounds or ends, except that a starting mark begins to have a required side when she is approaching the starting line from its pre-start side to start.