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Rule 18: Mark-Room at the Zone

Rule 18 of the Racing Rules of Sailing 2025-2028 decides who gets room at a mark. If boats are overlapped when the first of them reaches the zone, three hull lengths from the mark, the outside boat gives the inside boat mark-room. If they are not, the boat that reached the zone first is owed it.

RRS 2025-2028 · Rule 18, Mark-Room · Updated

Mark-room is room to sail to the mark and round it. It is not right of way: an outside boat on starboard or to leeward can still owe it to the inside boat. The zone is measured with the hull length of the boat nearer the mark.

Who is owed mark-room is fixed when the first boat reaches the zone, and an overlap gained after that changes nothing. Rule 18 stops applying between two boats once mark-room has been given (rule 18.1(b)).

Rule 18 switches off between boats on opposite tacks on a beat to windward, where rule 10 decides it, and at a starting mark surrounded by navigable water while boats approach it to start. That is why a boat barging in at the committee boat has no right to room.

A windward mark, an orange buoy labeled MARK, inside its zone, three boat lengths out, drawn as a white dashed circle with a light fill, with the wind blowing from the top of the frame. Two boats on starboard tack sail up to the mark from below, both inside the zone. The red boat, labeled INSIDE in green, is closest, its bow alongside the mark, about to round it with the mark on its port side. The blue boat, labeled OUTSIDE in amber, sails about a boat length farther out, leaving the inside boat room.
Rules Lab: the inside boat takes mark-room to round the windward mark to port.
A windward mark, an orange buoy labeled MARK, at the center of its zone, a circle three boat lengths out drawn as a white dashed ring with a light fill. Two boats on starboard tack, overlapped, are just reaching the edge of the circle, with the wind blowing from the top of the frame. The red boat, labeled INSIDE in green, is nearer the mark. The blue boat, labeled OUTSIDE in amber, is farther out.
Rules Lab: two boats reach the zone at the windward mark.

Sail it

Two starboard-tack boats fetch the windward mark overlapped, the inside boat to leeward. Sail the outside boat and give her room to round.

Try it in the Rules Lab

Questions

Who gets mark-room at a mark?

If the boats are overlapped when the first of them reaches the zone, the inside boat. If they are not, the boat clear ahead when she reached it. The outside or trailing boat gives the room.

Does an overlap gained inside the zone count?

Not for mark-room. Rights are set when the first boat reaches the zone (rule 18.2(a)(2)), so a boat that rolls up on the inside after that is owed nothing by the boat that got there clear ahead.

Does rule 18 apply between boats on opposite tacks?

Not on a beat to windward (rule 18.1(a)(1)): there rule 10 decides it, and port keeps clear. Reaching and running, it usually applies on either tack.

Paraphrased from rule 18 of the Racing Rules of Sailing 2025-2028, not quoted. The rule text is World Sailing's, and the rulebook is what a protest hearing reads.

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