Saturday, 27 February 2010

LTW Readers Q&A | 035; Port is slow to respond please be patient

From a Sunny Sydney – (b@b#s!h%sot) – a question from Neil, about that bloody windward mark – again (*^%#(*@)&@!#!!)

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During Club racing this situation has recently raised much debate and I would appreciate your thoughts. With many hours researching on the net I have never found this issue discussed.

The scenario.
  1. A windward mark to be passed and cleared to starboard (a clockwise direction).
  2. Boat A has entered the zone on port and will fetch the mark and with no others boats in the zone.
  3. Due to an adverse tide and a drop in the wind, Boat A slows at the mark and is still fetching the mark and does not need to tack for rounding.
  4. Boat B enters the zone on starboard (with a slight increase in wind strength) and hails Boat A to tack while barging inside Boat A at the mark and then Boat B tacks to round the mark forcing Boat A onto starboard and eventually Boat A tacking back on to port to round the mark.
Thanks,
Neil Johnson.

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Neil, this is what I came up with for the facts you’ve described:

100227 LTWR037 Boat Scenario file 100227LTWR035.xbs and animation: 100227LTWR035.gif

By your use of the word ‘barging’ I deduce that you might think that Yellow (Port)has some sort of protection from the Purple (SB) boat, by entering the zone so far ‘ahead’?

I’m afraid I must disappoint you. Rule 18 does not switch on, until position 6 (and there the Purple boat is inside boat with mark-room). The fact that Yellow has an adverse current and has trouble or is slow rounding the mark has no ‘standing’ in the rulebook. She must keep clear as port boat!

NO buts, maybees or otherwise.

And once she’s passed head to wind she must keep clear under rule 13 (tacking boat). Purple gains an inside overlap and is therefore entitled to mark-room under 18.2(a) – not 18.3, because she’s not fetching the mark – including room to tack because she’s overlapped to windward and on the inside of a boat required to give mark-room.

I would understand if you now started cursing yourself, but please keep it civilized. Nanny Ogg would say: “Bugger all that, lets curse someone”

Thanks for you contribution to LTW!
J.

Next time in LTW Readers Q&A: Sheeting in a Laser


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3 comments:

  1. Why to complicate your life with R18???
    It's only a R10 until the port boat (passing throught R13) is not tacking on starboard.

    ReplyDelete
  2. does RRS 18.3 have any application in this scenario?

    ReplyDelete
  3. Rule 18 (and hence rule 18.3) does not apply at all between the boats while they are on opposite tacks (rule 18.1 (a) and/or (b)).

    @5 rule 18 OFF (rule 18.1(b) at least).

    @5.5 to @6 Yellow has passed head to wind (HTW) and rule 18 is ON, but Yellow has not yet reached close hauled, so is give way boat (rule 13), outside of Purple, but Purple is not fetching the mark so rule 18.3 does not apply. Yellow must keep clear of and give mark-room to Purple (rule 18.2(a)).

    @6.5 Purple has passed HTW, rule 18 is OFF (rule 18.1(b)), but boats are on diverging courses, so it doesn't matter (unless some honknig tide swept Yellow back towrds Purple and the mark).

    @7.5 Yellow passes HTW, rule 18 is ON, but Yellow is now so far from the mark and Purple that she is certainaly giving Purple the mark-room to which Purple is entitled.

    ReplyDelete

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