Question 1
When a boat’s proper course is no longer to sail close to the mark, how much room (“space”) is she entitled to in order to round or pass the mark and still be considered to be sailing within the mark-room to which she is entitled, and therefore eligible for exoneration by rule 43.1(b), if she breaks a rule of Section A of Part 2, rule 15, 16, or 31?

Answer 1
The definition Mark-room is: “Room for a boat (a) to sail to the mark when her proper course is to sail close to it, (b) to round or pass the mark on the required side, and (c) to leave it astern.”

The definition Room is: “The space a boat needs in the existing conditions, including space to comply with her obligations under the rules of Part 2 and rule 31,while manoeuvring promptly in a seamanlike way.” Therefore, “mark-room” includes “room to round the mark in a seamanlike way.”

Under “Terminology” in the Introduction to The Racing Rules of Sailing, it states: “A term used in the sense stated in the Definitions is printed in italics…Other words and terms are used in the sense ordinarily understood in nautical or general use.”

A dictionary meaning of the verb “round” is: “pass and go around (something) so as to move on in a changed direction.”

Words and terms used in The Racing Rules of Sailing are used in the context of a body of rules that apply to the sport of sailboat racing.

In the context of the sport of sailboat racing, “to round the mark in a seamanlike way” means to change direction at a mark as needed to begin sailing on the next leg of the course on a heading consistent with sailing at the boat’s optimum angle to the wind. And a boat entitled to “mark-room” is entitled to the space she needs to make that maneuver in the existing conditions, including space to comply with her obligations under the rules of Part 2 and rule 31, while maneuvering promptly in a seamanlike way, and no more space than that.

Here are some scenarios applying that interpretation of the definition Mark-Room:

Scenario 1
When bearing off to round a windward or an offset mark onto a leeward leg where boats will need to sail on both tacks to reach the leeward mark, a boat is entitled to just enough space to turn promptly in a seamanlike way to a course consistent with sailing at the boat’s optimum angle to the wind without changing tacks. Mark-room does not include any additional space to gybe and sail on the other tack.

In Diagram 1, Boat A is entitled to mark-room. But because A does not need to gybe and sail on port tack to begin sailing the next leg on her optimum angle to the wind, mark-room does not include room to gybe and sail on port tack during her rounding maneuver. If A gybes and sails on port tack and breaks rule 10, she is not exonerated by rule 43.1(b) for her breach.

Note: If a boat clear ahead wishes to gybe around the windward or offset mark, she can consider sailing a little high of the mark on the approach and then sailing close to the mark before gybing such that a boat astern cannot prevent her from gybing without hitting the mark herself. See Diagram 2

Scenario 2
When rounding a mark where it is necessary for a boat to gybe to sail to the next mark, such as the gybe mark on a triangle course or the last mark of a trapezoid course before the finish, she is entitled to enough space to gybe promptly and sail in a seamanlike way on her optimum angle to the wind on the other tack.

In Diagram 3, Boat A is entitled to mark-room. Because A needs to gybe and sail on port tack to sail directly to the next mark, mark-room includes room to gybe promptly and sail on port tack during her rounding maneuver.

Scenario 3
When rounding a leeward mark onto a windward leg where boats will need to sail on both tacks to get to the next mark, a boat is entitled to enough space to promptly turn from a downwind course up to a close-hauled course (her optimum angle to the wind), but not space to turn up to head-to-wind or to tack. See Case 118. However, if boats must tack in order to sail directly to the next mark, they are entitled to space to turn up to head to wind, but not to pass head to wind, because rule 18.2(a) no longer applies when boats entitled to mark-room pass head to wind (see rule 18.2(b)).

In Diagram 4, Boat A is entitled to mark-room. Boat A sails wide of the mark, leaving space for Boat B to sail between her and the mark. Mark-room includes room for A to sail up to a close-hauled course. If A sails above close-hauled, she is not sailing within the mark-room to which she is entitled, and if she breaks rule 16.1 when doing so, she is not exonerated by rule 43.1(b). See Diagram 5.

Question 2
At a windward rounding mark, when a close-hauled boat is either overlapped inside and to windward, or clear ahead, of a boat that is required to give her mark-room, and she needs to tack in order to round the mark, is she entitled to mark-room after she has passed head to wind?

Answer 2
No. When a boat has sailed to the mark and will need to tack to round it, mark-room includes room to tack. However, the rule that entitles her to mark-room isrule 18.2(a), which no longer applies when the boat entitled to mark-room passes head to wind (see rule 18.2(b)).Therefore, in effect, an inside boat is only entitled to mark-room until she passes head to wind.

Note: This does not mean that an inside, windward, overlapped boat (W) cannot tack to round the mark. If W is overlapped inside an overlapped leeward boat (L), L must give W room to luff up to head to wind. In most cases, W’s luff will carry her far enough to windward that she will have room for her stern to swing without touching L as she tacks by continuing to turn until she is on a close-hauled course. If L luffs to try and prevent W from tacking, she risks breaking rule 16.1. And if, while W is sailing within the room to which she is entitled under rule 16.1, she breaks rule 13, she is exonerated by rule 43.1(b).

And if the boat entitled to mark-room (A) is clear ahead of the boat required to give her mark-room (B), A may luff up to head to wind and, in most cases, B will continue on port tack until her bow has passed A’s stern, at which time A will have room to tack onto starboard.

See Diagram 6.

Question 3
At a finishing mark at the end of a downwind or reaching leg, what is the “maneuver” that Boat P is entitled to make under rule 18.2(a)(2) and the definitions Mark-Room and Room in Diagram 7 below? Also, how do the rules apply in this incident?

Answer 3
When Boat P reaches the zone, Boat S has not reached the zone yet. Therefore, S is required by rule 18.2(a)(2) to give P mark-room. Because P’s proper course is not to sail close to the finishing mark, P is not entitled to room to sail to the finishing mark. But, under rule 18.2(a)(2) and the definitions Mark-Room and Room, P is entitled to make the following maneuver: sail promptly in a seamanlike way on a course that passes the finishing mark and leaves it astern. S complied with rule 18.2(a)(2) by giving P mark-room. P broke rule 10, but because the course P chose to sail to pass the mark and leave it astern was a seamanlike course, P is exonerated by rule 43.1(b) for her breach.

Question 4
In the definition Mark-Room, when does a boat ‘leave the mark astern’, for the purposes of rule 18.1(b), When Rule 18 Applies?

Answer 4
A boat leaves the mark astern when the mark is behind a line abeam from the aftermost point of her hull and equipment in normal position. However, if while maneuvering in the zone a boat temporarily leaves the mark astern, only when she leaves it astern after rounding or passing it on the required side as needed to begin sailing the next leg has she been given mark-room.

At position 2, Boat A has left the mark astern. However, she has not rounded the mark yet, so she isstill entitled to mark-room. At position 3, A is alongside the mark and isstill rounding it, so she has not yet been given mark-room. At position 4, she has left the mark astern and has been given mark-room. 

June 2025