RULE 18
Mark-Room
At a mark, an outside boat must give the inside overlapped boat room to round it.
When boats are overlapped as the first of them reaches the zone (a circle three boat-lengths around the mark), the outside boat must give the inside boat mark-room: room to sail to the mark and round it. If a boat is clear ahead when it reaches the zone, the boat clear astern must give it mark-room. Rule 18 does not apply between boats on opposite tacks on a beat to windward.
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mark-roomzoneoverlaproundingdownwind
How it interacts with other rules
- Rule 10 — On Opposite Tacks · see also
Section A right-of-way rules still apply at a mark except as modified by rule 18.
- Rule 16 — Changing Course · see also
A boat giving or taking mark-room must still obey rule 16 when changing course.