Monday, 24 February 2014

Back to the Basics (Part1): Keeping Clear

A blog post in a series: Racing Rules for Novices*
(*I'm going to try to do one of these on Mondays)

An explanation and cases for the definition "KEEP CLEAR"

In this series I would like to give you my insights into those issues in the Racing Rules for Sailing, that nine times out of ten are asked in one of my rules talks I do for clubs, sailors and/or class organisations, during the winter season.

KEEP CLEAR; one of the definitions in the rulebook;
Let me start by telling you that it is NOT the same as in, for example, the traffic rules. One car has right-of-way, the other car SHALL give priority to the right-of-way car and do nothing to interfere with its normal operation, wherever (within the boundaries of normal traffic) that car may want to go.
Giving priority: allowing certain drivers to proceed without obstructing their way; (From Road traffic signs and regulations in the Netherlands)
In the RRS the "keep-clear" boat has (only) a very specific set of obligations to fulfil, which are a lot less than never interfering with the "right-of-way" boat (ROW boat). If a boat keeps doing those obligations, nothing more, nothing less, she is doing what the rules say she must and she does not break a rule in Part 2, section A. She is then, by definition, "keeping clear".

Lets analyse what is written:
Keep Clear A boat keeps clear of a right-of-way boat
(a) if the right-of-way boat can sail her course with no need to take avoiding action and,
(b) when the boats are overlapped, if the right-of-way boat can also change course in both directions without immediately making contact.

So whether the keep-clear boat fulfils obligation (a) is depending on the ROW boat. That boat must be able to sail her course - the course she chooses to sail - without having the feeling that she cannot do this, because there is another boat she needs to avoid.

Now the first thing you might want to ask is; One helmsman is not the same as another helmsman?
A beginner might feel the need to avoid much sooner that an experienced skipper. In a big boat you might want to avoid sooner than in a small boat.... Alas, the rules do not specify.
If you take the risk of getting close to a right-of-way boat, you take on the risk that she might feel the need to take avoiding action. There is a limit of course. Any PC will want to have an  understanding that the ROW boat indeed reasonably might feel that need to avoid.

What about a save distance?
Six boat lengths is fine, nobody will reasonably think that a right-of-way boat needs to do anything. One boat length might be too close and half a boat length is most likely getting you into trouble. It also depends on where the closest distance occurs.

Port passing in front of Starboard
Port passing behind Starboard

Ten centimetres passing in front of a right-of-way boat is NOT keeping clear, ten centimetres passing behind a right-of-way boat, is.

The most talked about case in the Casebook is Case 50, dealing with exactly this issue. In short: If a port tack boat passes in front of a starboard tack boat, and the latter changes course, claiming she felt the need to take avoiding action, the port tack boat must convince (read: proof to) the PC that the course change by the starboard tack boat was unnecessary. If Port cannot do this, she is NOT keeping clear. Even if the shortest distance was several meters.
If you "get" case 50, you understand part (a) of the definition.

In short, there is no fixed distance. But the closer you get, the more risk you take.

Obligation (b) is a little more complicated.

When boats are overlapped, most likely they are sailing on a parallel course, next to each other. No matter how close the keep-clear boat is getting, as long as the ROW boat is sailing a straight course, the windward boat is fulfilling obligation (a). The ROW boat CAN sail her course without the need to take avoiding action. Save it for situations involving heavy seas, that distance can be pretty close. Certainly less than half a boat length.

Is Windward still keeping clear all the time?
Nevertheless is the windward boat - the keep-clear boat under rule 11 - in this situation, NOT keeping clear, now under obligation (b). The ROW boat must be able to change course (in both directions) WITHOUT immediately making contact. From position 3 to 6 the leeward boat cannot luff (or bear off) without immediately hitting the windward boat.
Be aware, under the current rules you can also have an overlap with a boat on opposite tack! For instance, when both are sailing a course below ninety degrees from true wind.

This brings us to the rest of the Casebook. Besides the already mentioned Case 50, there are five more dealing with the definition of "keep clear" specifically:

Case 30 
A boat clear astern that is required to keep clear but collides with the boat clear ahead breaks the right-of-way rule that was applicable before the collision occurred. A boat that loses right of way by unintentionally changing tack is nevertheless required to keep clear.
(pillow)Case of the week (51/11) – 30

Case 60
When a right-of-way boat changes course in such a way that a keep-clear boat, despite having taken avoiding action promptly, cannot keep clear in a seamanlike way, the right-of-way boat breaks rule 16.1.
(pillow)Case of the week (34/11) – 60

Case 77:
Contact with a mark by a boat’s equipment constitutes touching it. A boat obligated to keep clear does not break a rule when touched by a right-of-way boat’s equipment that moves unexpectedly out of normal position.
(pillow)Case of the Week (36) – 77;

Case 88
A boat may avoid contact and yet fail to keep clear.
(pillow)Case of the Week (27) – 88;

Case 91
The fact that a boat required to keep clear is out of control does not entitle her to exoneration for breaking a rule of Part 2. When a right-of-way boat becomes obliged by rule 14 to ‘avoid contact . . . if reasonably possible’ and the only way to do so is to crashgybe, she does not break the rule if she does not crash-gybe. When a boat’s penalty under rule 44.1(b) is to retire, and she does so (whether because of choice or necessity), she cannot then be disqualified.
(pillow)Case of the Week (17) - 99

[Note: I still have to update all the cases with the terminologies of the 2013-2016 rules. Don't worry, the principle (outcomes) in all cases have not changed. If you want to read the latest text, please have a look in the new Casebook. You can find it here on the ISAF website: The Case Book]

Back to the NOT interfering I mentioned in the beginning. Nowhere in the definition of keeping clear is anything written about "not interfering". As long as the keep-clear boat fulfils her obligations (a and/or b) she CAN interfere with the right-of-way boat. In fact, match racers do nothing else but interfere and usually as the keep-clear boat.

If you have specific situations or questions, please don't hesitate to email or write a comment.

Next week (Part 2): Where's the referee?



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