Saturday, 19 January 2008

An unusual Mark rounding

A couple of years back at Kiel we (the portest panel I was in) had a very unusual case involving 3 boats and a leeward mark rounding. I've put it in a TSS-diagram and here are two pictures. static and animated.
Facts Found:
  • Yellow, Green and Blue, all Finns in Race 3 on Course E with 2 Beaufort and calm Sea, all approaching the leeward mark (4) on Port Tack.
  • Yellow entered the 2 LZ when Green was 4 BL and Blue 6 BL astern.
  • There were several boats in front of Yellow, with very low speed, rounding the mark.
  • Yellow luffed beside the mark, inside the 2 BL zone, to head to wind.
  • Green entered the 2 BL zone with Blue 1 BL astern
  • Yellow passed head to wind and bore off.
  • Green sailed a course between Yellow and the mark
  • Yellow gybed when Green's bow was next to the mark
  • Green rounded the mark, Yellow luffed to a reach
  • Green passed the mark, Blue sailed a course between Yellow and the mark
  • Yellow luffed to close hauled, Blue also luffed very hard and hit the mark
  • There was contact between the starboard front end of Yellow and the port front side of Blue, no damage.
  • Both Yellow and Blue protested, no two rounds penalty were taken by either boat.
You can download the TSS-diagram here. If you play it in animation, perhaps it gets a little clearer.

The reason that Yellow didn't round the mark when she first arrived, was that there were a couple of boats parked there, and rounding at that moment for Yellow would have taken her a long way round, with the added disadvantage that she would have come out leeward of them as well. Instead Yellow decided to wait and do a circle inside the two lengths zone next to the mark. The panel I was in, all but decided - including me - that Blue had broken 18.2(c) , when one, who also was an IU, asked: What about Yellows tack?. Yellows tack? He entered clear ahead.... but wait, you are right, he did a full circle including a tack and a gybe.
Can you figure out who was disqualified?


  1. Hi Jos,

    Because the yellow boat tacked inside the 2bl-zone 18.3 could be applicable. However I don't think it is because 18.3 says that it applies to two boats where one of the boats is 'fetching the mark' (third line).

    According to case 33, the last line, a mark being passed to leeward is not being 'fetched'. Therefore I don't think 18.3 is applicable and I would go back to 18.2c.

    Blue had to keep clear from Yellow because Yellow was clear ahead at the 2bl-zone. Yellow could luff as she pleased, according to 18.2d. Therefore I would disqualify Blue for not keeping clear.

    What was your decision?

  2. RRS 18.3 is not applicable because the boats are approaching the mark on the same tack. (first sentence)

    I will wait a bit before I give you the conclusions and decision of that panel, to give others a change to comment, oké?

  3. I doubted about that one but Yellow is also on port-tack right after her tack. At that moment Blue is also approaching the mark.

    When is the snap-shot that decides if two boats were approaching a mark on opposite tacks? Is that snap-shot only made once or can there be several times?

  4. The snapshot is taken when boats are approaching the mark, which can be 3 or 4 lengths from the mark (in very fast boats like catamarans) but definitely close to or entering the two lengths zone.
    In this case Yellow has entered the 2 BL zone and changes her tack inside it. Definitely not rule 18.3

  5. Ok thanks for the response... and now I see I made a stupid mistake!

    In the last sentence of 18.2c there is the usual exception. 18.2c is no longer, and will be no longer applicable when the boat that was clear ahead passes head to wind, which is the case here.

    After Yellow passes head to wind Blue gets an inside overlap with Yellow in situation 7. With 18.2c no longer applicable we're falling back to rule 18.2a and Yellow had to give room to Blue to round or pass the mark.

    Blue had to luff so hard that she touched the mark so I don't think Yellow gave enough room and she should be disqualified.

    Shame on me for not seeing this sooner :(

  6. Don't feel too bad. This was exactly what happened to us in Kiel. Because a boat almost never does a tack before a leeward mark, we didn't think of it until one of us asked that question.

  7. I reviewed this further and want to add couple more key facts:

    Yellow completed her tack to port before Blue entered the 2 length zone
    Yellow gybed to starboard as Blue entered the 2 LZ.

    Yellow as outside boat and overlapped did not give Blue room to round the mark.

    Yellow is DSQ RRS 18.2a

    This is a new twist. Interesting to see what the decision was.

  8. Baltic Bandit (SA)7 June 2008 at 06:15

    I just talked through an exactly similar incident with Dick Rose, one of the sailing rule authors.

    His overall point is that this sort of Uhoh complexity does happen. But the key here is that Yellow established its overlap with the rest of the boats early on and that overlap never gets broken, and since yellow never leaves the 2BL circle, Blue has to give Yellow room to round inside.

    Blue can try and sail inside but can be forced into the mark

  9. One could not make up this kind of scenario - fact is stranger than fiction.

    The snapshot for R18.2(b) takes place when the first boat enters the zone. But Yellow's tack renedred that snapshot moot becasue R18.2(b) ceased to apply.

    Yellow had rights upon entering the zone and clear ahead of green and blue.
    If yellow's proper course was to tack in the zone, which arguably it was, it lost the rights of R18.2(b) because R18.2(b) does not apply when proper course for one is to tack.

    R18.2(a) would apply and control with the inside boat having rights over an outside boat, regardless of when the overlap occurred. (Yellow's overlap with green and blue was constantly changing due to the tack. At some point yellow had to be both clear ahead and clear astern of green and blue while inthe zone.) Yellow lost its rights of 18.2(b) when it tacked while sailing a proper course.

    Disqualify yellow because it did not give blue room to round the mark. Blue is exonerated for hitting the mark.

  10. hi what was the decision of the jury?

    I'd go with everyone else - the simplest. yellow failed to give room.

  11. Between position 5 and 6, Yellow gybes to S tack and Green is still on P just arriving at 2BC.
    Green gybes into a barging condition arguably into space "freely given", and overlapped to windward (not from astern!). Then at position 8 Yellow shuts the door by luffing into Green in a lock-up position (nowhere for Green to go to keep clear). Yellow also fails to keep clear regardless of ROW, even though she could have.
    - Philip


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