From: guido@blink.att.com (Guido Bertocci)
Subject: Re: rules definition question
Organization: AT&T
Date: Fri, 4 Sep 1992 14:18:12 GMT
Keywords: rule definition

jeff@unix386.Convergent.COM (Jeff Beckmann) writes:


>I have some questions regarding a few RACING definitions.
>I have my 1989-92 International Yacht Racing Rules in front of me,
>and can't find a few things that are key to an arguement I overheard
>after last night's beercan in Santa Cruz between my skipper and
>that of another boat.

>Winds were a little funny last night.  We reached to the leward mark,
>and we reached to finish.  We were about 8 boat lengths from the leward
>mark when our bow crossed the imaginary line drawn abeam from the stern
>of the boat ahead of us (most people would say we had overlap).  He was
>windward and wanted room at the mark.  Both boats were starboard tack.
>We were quite a distance from the other boat (about 3 of his boat
>lengths).  My skipper claims that overlap is a definition that the
>boats be neither clear ahead or clear astern AND within 2 boat lengths
>from the other boat.  The other skipper claims the same definition, but
>3 boat lengths.  The other skipper was yelling overlap, we were yelling
>"not within 2 boat lengths of a mark".  We became clear ahead about 4
>boat lengths from the mark.  Later the two skippers were argueing about
>the definition of overlap.

The definitions of overlapped are independent of the distances separating
the boats with two exceptions.  The basic point is that if two boats
aren't close to each other, it doesn't matter what they do.

Anyway, the exceptions are:
Rule 38.2.b.  For the purpose of rule 38 (luffing rights) an overlap does 
not exist unless the yachts are clearly within two overall lengths of the
longer yacht. 

    This makes it possible for a leeward boat who has lost luffing rights
    (i.e. mast abeam) to reestablish them by going more than two boat lenghts
    to leeward and coming back up (ahead of mast abeam).


Rule 39: A yacht that is on a free leg of the course shall not sail
below her proper course when she is clearly within three of her
overall lengths of a leeward yacht or of a yacht clear astern
that is steering a course to leeward of her own.

    This prevents a windward boat from drifting down below her proper
    course to stop a boat from passing to leeward.  Note that this
    is only on a free leg of the course, so it is perfectly legal
    to steer low while going to windward.  This rule is difficult
    to enforce due to the fairly wide latitude in defining proper course.


In terms of how far two boats can be to establish an overlap with
regards to getting buoy room, there is no limitation.
Conceivably, when the OUTSIDE boat hits the two boat lengths circle
you check to see if there is an overlap.  The other boat could be
10 boat lengths away have an overlap and still be entitled to room.  
(This will require some pretty oblique angles between the two boats and
can happen if the outside boat is running while the inside boat is
coming up quickly on a close reach.)

This means that both skippers were sort of right and sort of wrong. :-)
However, I don't quite understand the potential encounter.  
You were behind on a reaching leg and passed the guy to leeward.  
The other boat was to windward and had there been an overlap
at the mark he would have been entitled to room.  Asking for
room at a mark while 3 boat lengths apart and still 8 lengths from
the mark seems a bit over anxious.  (You did say light air?).
The only complaint I can see is if the windward boat was
steering low to stop you from going under them.  (Rule 39)

Paradox: Can two boats be clear astern of each other?  (yes)
	 Can two boats be clear ahead of each other?  (yes)
	 Can one boat be clear ahead while the other is overlapped?) (no)

	 (Only two boats in the picture, no third boats)


>On page 10 of USYRU's IYRR I find the following:

>************************************************************************
>Clear Astern and Clear Ahead; Overlap - A yacht is clear astern of
>another when her hull and equipment in normal position are abaft an
>imaginary line projected abeam from the aftermost point of the other's
>hull and equipment in normal position.  The other yacht is clear ahead.

>The yachts overlap when neither is clear astern; or when, although one
>is clear astern, an intervening yacht overlaps both of them.

>The terms clear astern, clear ahead and overlap apply to yachts on
>opposite tacks only when they are subject to rule 42, Rounding or
>Passing Marks and Obstructions.
>************************************************************************

>I see nothing limiting the distance between the boats in the
>definition.  As I see it, we had an overlap.  Since we were clear ahead
>before entering 2 boat lengths from the mark, he could not call for
>room at the mark.
Correct.

>Later on we were in a channel.  The boom was on the port side (with
>the wind coming over the starboard side).  Spinnaker was up with
>the pole on the starboard side.  We were sailing by the lee (what I
>mean by that is the spinnaker sheet was against the headstay).
>The skipper did not want to gybe the pole because that would put
>us on port.  I did not think the pole had anything to do with your
>tack.  I thought the boom was the only relevent data point.  I can
>not find the definition of port or starboard.  Can anyone point in
>the right direction?  I'm also curious, what if you only had a jib
>up?  What if you only had a spinnaker up?

Look at the definitions and combine the "on a tack" definiton with
the "leeward and windward" definition.  The main is the deciding 
factor.
Rule 64 requires that the spi pole be opposite the boom.
If there is no main, the rules aren't clear, however, one can
extrapolote that with the spinnaker up, the pole is opposite
the (nonexistent) boom and thus would define windward and leeward.
A jib alone would be treated as a single main.
(class rules can change these rules)

I would interpret the rules as saying that windward and leeward are
always defined and if the main is present it is the deciding factor
otherwise the other sails can be used to define windward and leeward.

>The more I think about this one, I bet our skipper thought we meant
>gybe the boat (boom and spinnaker) when we said gybe the pole.

>I'm only interested in the RACING definitions.  I'm not interested
>in what crusers or anybody else think the definitions should be.

>I'm not interested in "I don't race, but you should always have an
>adequate watch", unless you can point to IYRU or USYRU references that
>explicitly says that.  I'm not trying to be a jerk, but it doesn't
>help me to have the wrong question answered.  I don't have any updates
>to the rules (my understanding is every year an addendum or such is
>published) or published protest cases, but I will get my hands on
>anything that I am directed towards.