Another way of looking at it, if the other boat tacks in front of you into a right of way position, you do not need to begin to alter your course until she is established on her new close hauled course (i.e., completed the tack). If you have to avoid her before she has completed her tack, then she has fouled you. If she has completed her tack and given you enough room to keep clear, then she has not fouled you (even though her sails may not be trimmed and she may not be up to speed).

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