Question
A approaching from port, tacks ahead and to leeward of X inside the two-length
zone of a port-hand windward mark. At position 1 X bore away for the mark,
but after A completes her tack X has to luff and sail above close-hauled at
position 5 to avoid A. X protests. What should the call be?

Answer
X’s change of course at position 1 does not break rule 16.2 because A does not have to change course immediately to keep clear.
X is fetching the mark and A completes her tack inside the two-length zone. Rule 18.3 therefore applies, and by causing X to sail above close-hauled to avoid her A breaks rule 18.3(a). The fact that X bore away at position 1 does not in any way lessen A's obligation under rule 18.3(a) not to cause X to sail above close-hauled to avoid her. Penalize A.