Situation
Blue passed head to wind, from port to starboard tack, in the zone of a mark to be left to port, and was then fetching the mark. After completing her tack, Blue was clear ahead of Yellow and there was enough room for Yellow to either luff or bear away in a seamanlike way without any contact. Yellow didn’t change her course and after position 3 there was contact between her bow and Blue’s stern without damage or injury. Yellow was protested and was disqualified for breaking rules 12 and 14.

Question
Did Blue break rule 18.3?

Answer
No. 
Blue did not cause Yellow to sail above close-hauled to avoid contact and Yellow did not become overlapped inside Blue. Therefore Blue did not break rule 18.3. No other parts of rule 18 apply to the situation.