Tactical Rounding with Mark-Room? | 2

Since we are having a discussion about Mark-room in this post: Tactical Rounding with Mark-Room?, I thought it prudent to give you the exact text the working party - the ones who wrote the new rules 18,19 & 20 - said about this issue:


Mark-Room – A comparison of the old and new rules with respect to what ‘room’ a boat is obligated to give while sailing to or at a mark:

The old rules required boats to give ‘room’. The meaning of ‘room’ for the purposes of old rule 18 was stated in two sentences located in two widely separated places in the rulebook – in the Definitions section in the definition Room and in the preamble to rule 18.
New rule 18 requires that a boat obligated to give room give ‘mark-room’, a new defined term.
The amount of space that constitutes ‘mark-room’ depends on where the boat entitled to receive mark-room is located. Before a boat entitled to mark-room is ‘at’ the mark she is entitled to ‘room to sail to [it]’. While she is ‘at’ the mark, she is entitled to ‘room to sail her proper course’. (The use of ‘to’ and ‘at’ in the definition Mark-Room is discussed in more detail below.)

The old definition of room at a mark was incomplete; the new definition Mark-Room is not. The old definition lacked two important features, both of which are covered by the new definition.

1. The old definition only granted room for an inside boat ‘to round or pass between an outside boat and [the] mark’, and it was silent on what room, if any, was granted between the time one of the boats entered the zone and the time the inside boat needed space between the outside boat and the mark. The new definition covers both those time intervals.
2. The old definition stated that it covered room ‘in rule 18.’ Old rule 18 imposed requirements to give room on ‘outside’ boats and also, in old rule 18.2(b), on boats clear ahead or clear astern. However, the old definition only specified room that an outside boat was required to give an inside boat. Thus, it was not at all clear what the obligation to give room meant for a boat clear ahead or a boat clear astern that was required by rule 18.2(b) to give room.

The new term ‘mark-room’ only applies to the space that must be given under new rule 18, and that new rule applies only at marks (including marks that are also obstructions). However, if a mark is a continuing obstruction, then new rule 19 applies and new rule 18 does not. At obstructions that are not marks and at all continuing obstructions (including those that are marks), new rule 19 applies, and it only requires an outside overlapped boat to give ‘room’ and not ‘mark-room’.

The new definition Mark-Room answers a question that competitors have been asking for many years. It makes it clear at what time an outside leeward boat with luffing rights may no longer luff an inside windward boat towards the ‘wrong’ side of a mark. Consider two overlapped boats running on port tack to a leeward mark to be left to port. After one of the two boats is in the zone, the leeward boat is obligated by new rule 18.2(b) to give the windward boat ‘room … to sail to the
mark’ (see the first part of the definition Mark-Room). Inside the zone, if the outside boat were to luff the windward boat to a course taking her to the wrong side of the mark, the outside boat would not be giving the windward boat space to sail to the mark. Therefore, that luff would break new rule 18.2, even if the outside boat later bears off and lets the inside boat sail to the mark. If such an outside boat luffs the inside boat towards the wrong side of the mark before either of them is in the zone, then, provided she complies with rule 16.1 (and, if it applies, rule 17), the outside leeward boat breaks no rule. Under the old rules, there was no clearly defined moment at which such a leeward boat could no longer luff the windward boat towards the wrong side.

The use of ‘to’ and ‘at’ in the definition Mark-Room:

Several experienced sailors, upon reading the new definition Mark-Room, have asked what ‘to’ and ‘at’ mean in that definition. In the Terminology section of the Introduction, readers are told that words such as ‘to’ and ‘at’ that do not appear in italics are ‘used in the sense ordinarily understood in nautical or general use.’

Look in The shorter Oxford English Dictionary and you will find many thousands of words in fine print devoted to ‘to’ and ‘at’. We must ask what those words mean in the context of the definition Mark-Room for a boat that is sailing a course in compliance with rule 28. We picked the words ‘to’ and ‘at’ instead of several alternative words because anyone at all fluent in English has learned to use those two two-letter words accurately in a variety of contexts.
An easy to visualize, land-based analogy may be helpful. Suppose that you are driving your car north towards and then into a traffic circle or roundabout. Cars in the circle are required to drive counterclockwise around a paved ‘island’ in the middle of the circle. You plan to drive around the island until you can exit headed west. First, you drive to a point where the northbound road intersects the traffic circle’s circular road – i.e., to a point at which you can begin to round the paved island. You leave the traffic circle using the exit that takes you to the road headed west. The island is analogous to a rounding mark for a racing sailboat, and your car’s track into the circle, around the island and out of the circle is analogous to that of a boat sailing to and around that rounding mark leaving it to port.

To drive the ‘course’ described above, you will first need to drive ‘to’ the circle – that is, to a point from which you can enter the flow of traffic around the island. Once you reach that point, you are ‘at’ the circle. From there you enter the circular road and drive on it until you reach the point at which you leave the circle on the westbound road. Carrying this analogy out onto the water, a boat is sailing ‘to’ a mark until she is in a position close to the mark from which she begins the maneuver of rounding or passing it on the required side. From that time, until she
leaves the mark, she is ‘at’ it.

A boat entitled to ‘room to sail to the mark’ is entitled to the space she needs in the existing conditions to sail promptly in a seamanlike way until she is in a position close to the mark from which to begin the maneuver of rounding or passing the mark on the required side. If a third boat is inside her and she is obligated to give a third boat mark-room, then she must be given space to comply with that obligation. If the mark is moving in large waves, then she must be given space to sail to it without risk of it touching her. While sailing ‘to the mark’ if the boat entitled to mark-room is required to keep clear of the boat giving her markroom, then she is not entitled to the space needed to sail her proper course to the mark – i.e., the course she would sail to the mark in order to finish as soon as possible in the absence of the boat obligated to give her mark-room. However, from the position where she can begin to maneuver to round or pass the mark until she leaves the mark, she is entitled to space to sail her proper course.


You can read the whole paper from the working party (Dick Rose, Ben Altman, Chris Atkins, Rob Overton and Richard Thompson) here: Comparison of Old and New Section C Rules (2).pdf.

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