Wednesday, 26 November 2008

RRS 2009-2012; Rule 19 Room to Pass an Obstruction

In the new rule book (RRS 2009-2012) the old rule 18, about rounding and passing marks and obstructions, has been split into two rules: 18 dealing with MARK-ROOM and 19 ROOM TO PASS AN OBSTRUCTION.

I have had some inquiries and comments on what the effect will be of the new wording in rule 19, particularly for boats on the starting line. Let's first look at the rule(s):

Rule 19.2(b) States: 'When boats are overlapped, the outside boat shall give the inside boat room between her and the obstruction, unless she has been unable to do so from the time the overlap began'

Definitions: Obstruction; An object that a boat could not pass without changing course substantially, if she were sailing directly towards it and one of her hull lengths from it. An object that can be safely passed on only one side and an area so designated by the sailing instructions are also obstructions. However, a boat racing is not an obstruction to other boats unless they are required to keep clear of her, give her room or mark-room or, if rule 22 applies, avoid her. A vessel under way, including a boat racing, is never a continuing obstruction.

For a boat approaching from behind, the boats lined up on the starting line are obstructions. She has to keep clear under rule 12. If she finds a gap between two of those boats the situation changes. From the moment the clear behind boat establishes an overlap with the windward boat of those two boat in front, she is no longer keep clear boat to both of them, she only has to keep clear of the leeward boat. Initially she has to give the windward boat room to keep clear under rule 15 but then that passes and she becomes right of way boat.

Under RRS 2005-2008 the two front boats were also a continuing obstruction and the boat from clear behind could not force his way in between if there was no room to do so at initial overlap.

Under RRS 2009-2012, boats racing can no longer be a continuing obstruction, so that part is gone. We only have rule 19.2(b) to rely on. At the moment the overlap was established, the windward boat has to give room, if she is able to.

If there are boats to windward she cannot luff and give room, you say? I received an interesting article from Mike Butterfield addressing this very issue:

How will they start in 2009 – line length issues!
I was just looking at the new rules and changes for Team Racing, and came across a game change that could affect starting in yacht races. Present I am considering a start line, the boats are in ranks, with the first rank spread down the line. We are used to the cries of UP, UP, UP, and often inactivity on behalf of the windward boat. The rules were in some areas complex, in some simple.

Two Boats: With two boats one of whom comes from astern, there is a simple progression under the rules. Initially one boat is clear astern of the other and must keep clear. Then that boat establishes a leeward overlap, and the windward boat must now keep clear, but initially the leeward boat has to give “room” to the Windward boat (RRS15) to do so. The windward boat must do all possible which may be to luff but may be to accelerate to keep clear. This can cause boats to be OCS.

Three boats: If there are three boats in the area with the two boats in the first rank just over a boat width apart, then the leeward boat is a continuing obstruction to the windward boat and the boat approaching from astern. This means that the leeward boat now cannot intervene unless at the time the overlap is established there is room to pass between the boats. RRS 18.5.

This means the boat approaching cannot enter the front rank, and in these circumstances cannot oblige the windward boat to accelerate to keep clear. This assists in regulating the start.

Two Boats: There is no change here.

Three boats: This is where the change is, the leeward boat cannot be a continuing obstruction (definitions) so under new rule 19, the boat approaching from clear astern can always put the bow in. Here the leeward boat on the front rank is an obstruction and the boat putting it’s bow in is inside boat relative to the windward boat and entitled to room unless the windward boat has been unable to do so from the time the overlap began.
Here is the problem, the windward boat can always accelerate (as otherwise how could it start) over the line.

Here could be the start of what will look like line indiscipline as boats are forced over or subject to disqualification for not keeping clear. In regattas (especially in team racing) now two boats could work in concert with a friend establishing an overlap too leeward of a target boat, to force it over or protest it. The previous protection in a crowded front rank has now been lost.

Will be need longer start lines or will we be developing a Black Flag lottery?
Mike Butterfield IRO IU IJ

I would like to hear your opinion....



  1. My opinion? I agree with Mike. It will be a BF lottery

  2. I agree, when I first read the "a boat racing, is never a continuing obstruction" I thought "quite a change on the start line".
    Currently on a dinghy start line, you hear "no space don't go in there" by the windward/clear ahead boat quite often, sometimes the windward/clear ahead boat even bears off slightly, to narrow the gap to the leeward boat. Common practice and coaches are telling their sailors to do that.
    So quite some people will have to re-adjust.
    Makes it harder to protect your space on the line, but long term probably will make sailors look for their position later, as they can still get in, so maybe it will de-stress the start, as the line of boats forms later, maybe no more 50 seconds of fighting and screaming (and breaking 42 to move the bow around to close gaps and go up again) in the future. If it would become a BF lottery, more sailors will try to stay out of the lottery for as long as possible I guess.

  3. Lets say the front row is head to wind. They will all get going by backing their jibs and bearing away. This is not an option for the boat newly required to keep clear because it would take her towards the leeward boat. She cannot tack because of the boat to windward.

    I wondered about 'room to tack at an obstruction'. That would cause chaos. The rule says 'When aproaching an obstruction'. You might argue that the boat newly required to keep clear is not approaching the obstruction of the leeward boat. On the other hand, I am reminded of that old joke about Einstein asking 'When does Birmingham get to this train?'


  4. What exactly is meant by "Black Flag lottery".

  5. @Anonymous II:
    I think that Mike means with 'Black Flag Lottery' the unpredictability of who's going to be forced over by this tactic. If you have won a good place on the starting line, it can be completely undone by someone coming from behind forcing you to go over the line.... even with the black flag rule in force.
    Also frustrating for the RO because he can no longer predict from the group if there are going to be OCS's. It can happen anytime anywhere on the line...

  6. I am having a hard time seeing what difference the change in the definition will make at the starting line. When a boat tries to poke their nose in when there is no room they by definition are breaking rule 15.

    Rule 12 still applies to an overtaking boat so if you are clear ahead you can still aggressively alter course to protect your space to leeward. In my view the only rules that ever protected someone on the line are 15 and 16. 15 when the overlap first occurs and 16 as 15 lapses and the leeward boat tries alters helm after they have gained the right of way. They still will not be permitted to come in from clear astern and alter course if you have a boat to windward of you because they will still need to wait until you are able to respond, which may be never if it is the entire starting line.

    I think you are mistaken that the definition of obstruction ever offered protection in this instance.

  7. I am not sure about aggressively altering course to leeward. 16.1 applies. If the change of course results in the boat behind becoming overlapped to leeward, the boat in front has no protection from rule 15.


  8. Wag,

    Of course you cannot foul someone. But there is a lot you can do before the boat clear astern gets the overlap to protect your spot on the line within the limits of rule 16. But, the rules with respect to continuing obstructions never protected the boat on the starting line and I see no change in this instance by clarifying the definition in the new rules. I would argue that boats on the starting line never met the definition of a continuing obstruction under the 2005-2008 rules. Further, I would argue that it was always a stretch to classify any vessel as a continuing obstruction since they can be passed on more than just one side and this was a needed clarification.

  9. Norm,
    By definition the most leeward boat of three (or two and one clear astern) is an obstruction.
    There is no definition that a continuing obstruction can only be passed on one side.

    So if the most leeward boat (L) is an obstruction, 18 has to apply as L is not a starting mark, nor are the other two on opposite tacks or one of them has to tack to pass L.

    If 18 applied, but 18.5 (continuing obstruction) not, why do you need to protect the space to leeward, as long as it's less than 2 boat lengths, as clearly 18.2 (c) would apply and protect the Windward boat (W) quite nicely.

    So actually in the "old" rules, 18.5 took away rights from the Windward boat on the line, but still protecting it.
    But the new rules will limit the protection even further, basically to what you suggest, that it's down to 15 and 16 (well and of course new 19.2 (b)).

  10. Thank you Peter you have clarified for me why it was absolutely necessary to change the rules, there was a fatal flaw. I will try to make my case. First, you are correct there is no definition in the rules of continuing obstruction only “obstruction”, and you are correct under both the old and new rules a boat you are required to keep clear of or give room is an obstruction.

    Since “continuing” obstruction is not defined you need to use continuing in its commonly used sense. My dictionary defines an object as being continuing if it is “going on, or extending without interruption”. I argue that by the commonly used definition a leeward boat parked on the starting line is not and cannot be a continuing obstruction to a windward boat. An obstruction yes but a continuing one no.

    There are no ISAF cases that deal with leeward boats on the starting line as a continuing obstruction. I have seen some books and presentations that have claimed this, but they are only the opinion of the writer. You need to note that in the decision of ISAF case 16, L was deemed a continuing obstruction, “Because it would take some time pass her, L is a continuing obstruction to M and W”. Therefore, not all leeward boats are necessarily continuing obstructions. Only if it takes some time to pass them. This is a stretch of the definition of continuing in my opinion, but it was what they decided and it at least has some merit. But, in the absence of case to the contrary, I will still submit boats luffing to leeward on the starting line are not continuing obstructions to windward boats using continuing in its normal sense. Windward can always accelerated and get by them in short order.

    This gets us to the fatal flaw that Peter clearly pointed out, if 18.5 under the old rules does not apply, then 18.2 would, so there would be no need to protect your spot on the line if you are within 2 lengths of a leeward boat. This is obviously not how we start and it makes it clear one of the reasons to change the rules to clarify this situation. It would be interesting to know if this came up as one of the reasons for the change. This has been a very interesting discussion.

  11. I'm not a big fan of the new rules.
    However, I am willing to accept them.

    In your blog you say "the leeward boat is a continuing obstruction".

    In a later issue of your blog, you quote the definition of an obstruction: "A vessel under way, including a boat racing, is never a continuing obstruction."

    So how does your '3 boat' example really unfold?

  12. If section C rules don't apply to boats approaching to start, how does rule 19 have any bearing on the 3 boat scenario in 2009? Section
    A and B rules will control - do you agree? Clear astern is keep clear boat until she overlaps a windward boat then must initially give windward room to keep clear uner 15 and may not luff up under 16 without giving windward. room.


Related Posts Plugin for WordPress, Blogger...