IYRU Rule 17

[Guest]

Can someone explain Rule 17 to me please?

And if I understand it correctly, why no one obeys it?

Thanks.

[B00B00 310]

Proper course? Pretty well used and understood rule I thought.

Basically if you dont have luffing rights then you cant sail above your proper course. But the windward boat has to keep clear as long as the leward boat is still sailing its proper course which in many cases is higher than the windward boat( if leward boat is a gennaker and windward boat poled out spin).

[johnk 0]

to follow on from Josh ,

and you don't have luffing rights if that overlap was established from behind and to leeward

but as josh says the leeward boat is not luffing unless it is sailing above its proper course

and the windward boat has to keep clear and if it feels it is being infringed , by the leeward boat sailing above its proper course, its real option is to protest, if it doesn't continue to keep clear by possibly altering course (to avoid an illegal luff) it may find itself subject to protest for not keeping clear

[Guest]

I think everything that Booboo and John has said is correct.

 

As to your question as to why no one seems to obey it, I think it is because of a combination of:

 

1. It is a complicated rule - there are a number of conditions that have to be met, in combination, namely:

 

[*]The two boats must be overlapped; and

[*]The leeward boat must be within 2 boat lengths to leeward of the windward boat; and

[*]The overlap must have been established from where the leeward boat was clear astern (and note, this could be an unlimited amount of time ago if the overlap has remained unbroken since then, and

[*]It involves not sailing above a proper course.

 

It can be even more complex in multiple overlapped boats sitauations where the sandwiched boat's proper course is dictated by it's obligations under other rule eg rule 11 to keep clear of the boats to leeward of it.

 

2. The definition of a proper course is itself complex. It is:

 

( a ) subjective,

( b ) different for different designs, and in different conditions, and there can be more than one proper course for th same boat simultaenously, or

( c ) it can be unlclear as to which of two courses is in fact the boat's proper course - the shorter one in less adverse tide, or the faster longer one in more adverse tide as just one example of this.

[*]The case book shows that to determine a proper course you only look at the boats involved in this rule i.e. you ask what the course the leeward boat would sail in the absence of other boats nearby not affected in the application of this rule - which is extremely theoretical, and often contrary to the practical decision making on board at the time.

 

3. A lot of sailors are not very familiar with the rule book, let alone the more complicated rules like this one.

 

4. Even some sailors who ARE familiar with the rules, including this one, KNOW that 3. is true, and know that 2. is true, and therefore, when it suits them, leverage this and pretend to be unaware or unclear on it.... while a debate rages as to whether the rule does or does not apply, and if so what the obligations from it are and who needs to do what... all that time they are getting the advantage they want.

 

It is a classic example of a good idea, arguably poor implementation, and vagueness and hard to define / subjective factors meaning it's often just in the too hard basket.

[Clive 13]

There is a good article here: http://www.mysailing.com.au/news/downwind-dilemmas-the-rules-that-govern-overtaking

[Clipper 343]

Pretty common issue with asymmetric kites versus spin on the same course.

[SloopJohnB 323]

Test yourself here

 

http://www.uksailmakers.com/Education/Rules-Quiz.html

[Guest]

This one is also really good (in my opinion even better than the uksailmakers one, but that one is good too)

 

http://game.finckh.net/indexe.htm

[B00B00 310]

With all this talk of proper course, I must point out that if someone has luffing rights then they are still entitled to luff you head to wind as long as they give you room and opportunity to keep clear. Windward boat always has to keep clear.

[Guest]

The point being however, that when rule 17.1 does apply, you have a limitation on those luffing rights. i.e rule 17.1 says you may only luff (when it applies) up to your proper course, not all the way to head to wind...

 

...when it does nto apply, then it is you say Josh.

[Guest]

Thanks for all that!

Appreciated.

[Glsssbead 2]

Also, my understanding is that before the start gun, there is no proper course for the leeward boat to sail so it is free to luff-up the windward boat up until the start.

 

What I don't understand about this rule, was in the America's cup, I thought we saw the leeward boat keep attacking long after the start, which wouldn't be allowed based on my understanding - obviously I am missing something here though, so maybe someone can explain?

 

Thanks

[mattm 98]

Glsssbead, from my (limited) understanding, the rules are different for match racing. You can attack each other at any stage. I'm sure someone will have a technical explanation.... But don't try holding your opposition up for 30 seconds at the first mark at the opening night of rum racing....

[Guest]

It also ONLY applies if the leeward boat established the overlap from clear astern. If they did not, i.e. it was established during a tack or gybe or it was established from clear ahead, then rule 17.1 does not apply, and there is no proper course limitation on their luffing rights. So it could be that in those situations where the leeward boat kept above close hauled after the start gun that they were not limited by rule 17.1 because it did not apply.

[ex Elly 197]

Glassbead,

 

Do not apply what you see in the America's Cup, to your own racing. The rules are different.

For example, if you make an infringement you must do your penalty turns as soon as possible (NOT any time before the finish). Rule 44.2

 

Do not apply what you see in the Volvo Round the World Race to your own racing. The rules are different.

For example, do not stack sails or move heavy items from one side of the boat to the other. Rule 51.

 

Rules are here:

http://www.sailing.org/tools/documents/ ... 2016Final-[13376].pdf