After the tack, Red has been on a close-hauled starboard-tack course for long
enough, that Blue has had sufficient time to adjust to the new situation. Red
is not subject any longer to the limitations of rule
15, and Blue must keep clear under rule
10 (boats on opposite tacks), even if Red does not accelerate after the
tack. Therefore there are no valid grounds for Blue's protest. See also Case 17.