When the blue boat reached the zone, the red boat was clear astern. Therefore rule 18.2(b) and (c) requires the red boat to give mark-room and the red boat is not entitled to room, even if she becomes overlapped inside during the rounding. An infringement of rule 11 or rule 10 is exonerated by rule 21, because the gybe and luffing are part of the rounding manoeuvre on Blue’s proper course. Because the red boat did not give mark-room, she will be disqualified in a protest. If there was damage, it shall be investigated if Blue breaks rule 14. But in the moment, when it became clear that the red boat is not giving mark-room, it is difficult for her to avoid contact, but may be possible to minimise damage.