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Author Topic: Dolly (aka Darling) marks  (Read 17851 times)
Ken Smith
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sail often, travel light


« on: February 10, 2009, 08:09:22 AM »

There have been several table-discussions, over beverages, usually, about the use of Darling marks.

A darling mark is a sister mark to the rounding mark, placed to force competitors to tack or gybe no closer than that mark to the rounding point.  This would prevent tacks at the weather mark into traffic, gybes after the weather mark into incoming traffic, and move incoming starboard tack boats a bit away from the leeward mark.

The theory is that this would make the likelihood of collision less at the marks. 

It might go like this:

"At the discretion of the race committee, darling marks may be specified.  If darling marks are placed, they shall be placed approximately twenty meters down wind of the weather mark and/or twenty meters upwind of the leeward mark.  Competitors shall not pass between the darling mark and the rounding mark while racing, except competitors may pass between the leeward darling mark and the leeward mark after starting and before rounding the first weather mark.  The darling marks shall be considered mark s of the course for the purpose of the rules, and must be left to port in the course of rounding the adjacent mark, which also must be left to port. The placement of darling marks, if used,  shall have been specified in the racing instructions."
« Last Edit: February 12, 2009, 05:00:22 AM by Ken Smith » Logged

Ken Smith
DN4137US
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« Reply #1 on: February 10, 2009, 09:08:29 AM »

I believe the term is "Darling' marks, named after the gentleman who first had the idea about 50 years ago.

The problem with using Darling marks is that the NIA
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« Reply #2 on: February 10, 2009, 09:40:59 AM »

Sorry, I did not complete the previous comment before I accidentally hit "enter".

The problem with Darling marks is that the right of way rules under which we sail were designed for races sailed around windward leeward courses using two marks, not four marks. 

Carefully thought out amendments to the rules need to be implemented to accommodate using Darling marks.   If a class organization feels it important to consider the use of Darling marks, I suggest the class make a formal request to the board of directors of the National Iceboat Authority asking that a deliberate study be made as to what amendments would be required.

 Caution must be made to assure that the sailing rules are the same whether or not Darling marks are being used because sailors will forget what applies in a certain race and will not make correct decisions in converging situations.    Prior to the writing of the current NIA rules, each regatta used different right of way rules.  That is why the classes and associations appointed a committee to write one set of rules. 

The inside and outside boat at marks becomes a particularly critical issue when a tack or gybe is necessary to honor a Darling mark. 

When the wind shifts (which  happens during a race as well as between races), a Darling mark in the wrong place can be a disaster.

What rules apply when two boats are sailing on-the-wind on starboard tack and one boat is "laying" the Darling mark and one boat is not "laying" the Darling mark.  What if six or eight boats are in this situation? 

Similar issues occur with boats sailing off-the-wind.

A simple phrase "Do not sail through here" does not suffice (which essentially is what occurs when a Darling mark is used).  Rules need to clarify the responsibilities of each boat and how it must respond when a fleet is approaching the "do not sail through here" zone. 

I suggest that the size of a fleet be governed by the size of the available ice.  It seems to me that 50 boats on a course with the marks .8 miles apart is simply asking for trouble.  I believe the documents governing DN regattas give the governing committee the authority to reduce fleet size when necessary.  I fully understand that smaller fleets means more races,  but perhaps safer races.


...DN 805

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Ken Smith
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sail often, travel light


« Reply #3 on: February 10, 2009, 02:35:12 PM »

Hmm

One issue as what of boats that have no room or under-stand the weather mark, and must pass below that mark...

"At the discretion of the race committee, darling marks may be specified.  If darling marks are placed, they shall be placed approximately twenty meters down wind of the weather mark and/or twenty meters upwind of the leeward mark.  The darling marks shall be considered mark s of the course for the purpose of the rules, and must be left to port in the course of rounding the adjacent mark, which also must be left to port. The placement of dolly marks, if used,  shall have been specified in the racing instructions

Competitors shall not pass between the dolly mark and the rounding mark while racing, except:

  a)   competitors may pass between the leeward dolly mark and the leeward mark after starting and before rounding the first weather mark.  .

    b) a boat that fails to properly round the mark and passes to teh course side of that mark must turn keepint the dolly mark to port whenreturning to properly round the mark"
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Ken Smith
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Fredrik Lönegren DN S-8
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« Reply #4 on: February 10, 2009, 05:47:15 PM »

Not 20 meters
100-120 meters between the big mark and the Dollymark. Important to have that distance if they should do any effect on the safety.
Way wait!! Look into NIA rule A, that says you must use your common sense.
Good luck and try the Dolly marks at your regattas.
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BR/ Fredrik Lönegren Ph. or SMS +46 707 307 306
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« Reply #5 on: February 10, 2009, 06:25:26 PM »

Please consider a situation with 12 boats on-the-wind on the starboard tack and 12 on the port tack . all that are on the same tack sailing abeam of each other with no bow ahead of the other and only 50% able to fetch the darling mark.  Does the starborad tack windward most boat that is fetching the windward mark need to tack because because the leeward most boat cannot fetch the Darling mark?  Does the leeward most port tack boat need to lay off to allow the boats to windward of him leave the Darling mark to port?   When does the outside boat on each tack need to begin make room?    At a standard windward mark starboard tack has right of way over port tack.   Is the space between the Darling mark and the standard mark a "no sail" zone?  Is it classified as a mark or is it an obstruction?

Similar situation at the leeward end of the course.  Let's say the boats are on port tack coming to the leeward end of the course.  12 boats essentially even.  Does the windward boat have the right to lay off far enough to make sure he can pass both mark on the required side?    Seems like the windward boat would need to "float" down an awfully long way, and all the boats would need to "float" down with him.  The leeward boats would likely choose to gybe away and come back toward the leeward mark on starboard. 

What if its hard ice and blowing 22 mph?  What if is light air in sticky snow? 

Are you requiring too many maneuvers to be made as the fleet approaches the main mark and the Darling mark?   

Using a Darling mark is essentially doing little except expanding the diameter of the mark at each end of the course to the size of the combined marks and that diameter would exceed 100 meters.  I'd be surprised if you'd consider using windward or leeward marks that are 100 meters in diameter.   \

I repeat.  It cannot be easily resolved.
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Fredrik Lönegren DN S-8
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« Reply #6 on: February 11, 2009, 03:21:14 AM »

Dear Jane Try to bee more open minded. Look at the possibilities and the safety.
The mark is not a circle. It’s only a forbidden to cross between the marks.
Its working very well. We have using this for many years now and the safety and sports manna ship are better with dolly marks. Trust us we have the experience.

Example of sailing instructions that we been using in Europe, and its no problems at all.

Dolly marks" will be placed 100-125 meter from the leeward and windward mark. Note: It is always forbidden to cross between the smaller dolly marks and the bigger rounding marks.

Try it !!
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BR/ Fredrik Lönegren Ph. or SMS +46 707 307 306
Ken Smith
ADMIN

Posts: 290


sail often, travel light


« Reply #7 on: February 12, 2009, 05:39:10 AM »

Never tried it, but many discussions with those in the East and those in Europe that have.  At the NA annual meeting, the issue was discussed.  There were none that spoke against the idea of use of the darling mark, and the executive committee was directed to explore the use of the darling mark by a unanimous vote.

Positive:  This use of Darling marks moves the crossing situations at the weather mark, where those approaching on a port tack must find a way into the incoming starboard tack boats, well away from the mark itself. 
     
comment:  This is the point in our racing where a collision is more likely than at other points in the race and the collision involved has the highest potential of being violent and/or involving the largest number of boats.  It is also the point where most boats are either at their maximum speed or are accelerating into the mark for a high speed rounding.

Positive:  After rounding the weather mark, one could not gybe immediately and sail a course into the approaching starboard tack boats.  While the downwind boat is the give-way boat, moving this point well away from the mark reduces the possibility of a boat going head-on into a crowd of boats.  Thus, the likelihood of a head-on collision is reduced.


Positive:  This use at the leeward mark reduces the likelihood of a fast-moving downwind starboard tack boat seeking to round or finish into the crowd of port tack boats approaching to round or finish.  It moves the point where the starboard tack boat is likely to gybe further up the course where there is more room  to maneuver and the port tack boats are less likely to be tightly grouped, as they would be when converging to finish. 

Comment:  Our racing encourages most to set up for the leeward mark rounding on a port tack.  If a group is rounding and a fast-moving starboard tack boat appears before them, clearly that boat has right of way, but at our speeds and in crowd, in a situation where the boats are closest to skidding, the event could easily lead to a bad outcome.  The worst is if the starboard tack boat is finishing and the incoming port tack boats have crossed the finish line but still have a lap to do.  Both sets of boats intend to depart the area in different directions that conflict.

Positive:  In the course of the race, the use of the leeward darling mark eliminates the possibility of tacking at the leeward mark.  This reduces the chance of an up-wind starboard tack boat passing through a crowd of off-the-wind boats converging at the mark who must also now give way to the on-the-wind boat approaching, maybe nearly head-on.


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Ken Smith
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Ken Smith
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Posts: 290


sail often, travel light


« Reply #8 on: February 12, 2009, 06:15:05 AM »


Most of the negative have to do with extra equipment and race committee tasks.  Please add replies to place your opinions up for discussion!

Because the use of Darling marks has been discouraged by the NIA, there is a lack of resolved or appealed protests so some situations are a bit unclear, at least to me.  Perhaps some discussion of specific situations should follow, so all can understand what would have happened in certain situations.

1.  If approaching sailing on-the-wind on a starboard tack, a boat is unable to make the weather mark and has no room to tack because of those sailing to the weather mark to his right, he must either turn sharply down wind to avoid passing between the mark and the darling mark, gybe and sail back on port looking for a place to tack.  The Darling mark adds an obstacle, not an obstruction, to this.  If another boat to his leeward carries him across the line between the mark and the Darling mark, is he also disqualified?

2.  One of Jane's hypothetical situations:  consider a situation with 12 boats on-the-wind on the starboard tack all that are on the same tack sailing abeam of each other with no bow ahead of the other and only 50% able to fetch the [windward??]  mark.  Does the starboard tack windward most boat that is fetching the windward mark need to tack because because the leeward most boat cannot fetch the Darling mark?

Discussion:  On the wind, the windward boats must give way to the leeward boats on the same tack.  leeward boats may maneuver to windward as long as they are on the same tack.  Those that cannot make the weather mark have no new right to tack, but instead must gybe.  I don't see that fetching the darling mark is relevant.  However, if two boats (six boats in Jane's case) are in this situation, and the windward-most boat not fetching the weather mark seeks to gybe, there appears to me to be an issue as he is the give-way boat and could be forced between the weather and Darling mark by the leeward upwind boat(s).   How is this resolved in Europe or elsewhere when the Darling mark is used?

Note:  I could not understand the other situations in Jane's post or how the presence or absence of a Darling mark would change the outcome.  It seems to me the current rules make the obligations of each boat clear as it is now.
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Ken Smith
DN4137US
RANDY ROGOSKI
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« Reply #9 on: February 13, 2009, 04:57:47 AM »

Racers who keep a sharp lookout for other boats with a commitment to avoid collissions, even when having the right of way, are the key to safe racing.

Long race courses also are helpful because they spread the fleet out and reduce mark rounding traffic.

Most collissions occur because of a failure in vigilance, excessive risk taking at mark roundings, or disregard of the right-of-way rules.

My view is that the race committee has enough to do without having to also deal with dolly/darling marks.

They solve nothing for racers who remain careless.

Randy Rogoski
US 4192
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Capt Dave
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« Reply #10 on: February 22, 2009, 07:40:23 AM »

The original Darling mark was green, not far from the leeward mark and slightly to port on the course. and could only be passed through going to weather. Thats the way Jay Darling originaly set it up. mainly because of  the safety situations developing AT the race committee on finishes. fyi
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DN4287
Newbie

Posts: 9


« Reply #11 on: February 22, 2009, 03:17:05 PM »

I can understand the use of a Darling mark below the windward mark, but above the leeward mark seems ok for the first 2 laps but when finishing won't this force the Starboard Jibe boats that would now finish at the mark to sail further out above the finish line and thus push Port jibe boats further toward the Scorers?  Anything that will cause more boats to finish close to the Scorers should discarded - it bad enough now.  But maybe I'm not understanding how the leeward Darling is set. 

John
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Geoff Sobering
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« Reply #12 on: February 25, 2009, 05:28:58 PM »

[Posted for Eric Anderson, US-5193]

I don't think anyone starts a race thinking   "I would like to come screaming into the windward mark on Port today just to get my adrenaline going".   Racers starting in even positions  in the high 30's and40's are going to arrive  at the port tack windward  layline very soon after the start if the course is short,  and often have to wait for boats to windward to clear before tacking safely.

I am including a series of crude diagrams.  I don't have the time or ambition to make them pretty.

The first is what the race course looks like with  darling marks since most people have not seen or sailed them in North America. The second is a blow up of the windward part of the course with the port and starboard laylines illustrated.   I think this allows you to visualize what the course looks like with the darling marks.

To me the advantages are the following:

On starboard tack, any crossing with a port boat occurs  ~ 5+ seconds before you round the windward mark.  This allows you to focus on roundings and boats around you not port tackers.   Secondly any port tackers will be making a 90 degree course change not a 180 degree turn like they would at the port tack layline at the mark itself.   Secondly as you round the mark the downwind starboard layline should be well above the port tack upwind layline so you don't need to worry about that.   After you round, you need to sail a few seconds before you can gybe and go below the darling mark so you have plenty of time to look for boats sailing port tack upwind .

If you are sailing upwind on port, any boat already rounding the windward mark is well above you so is not a problem, when you pass the dolly mark, you have a gap to either tack below the fleet or find a hole to  tack into or sail through.  If a boat has rounded and gybed you still have several seconds from gybe to crossing so both parties can see each other.
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Man Why You Even Got to Do a Thing
DN4287
Newbie

Posts: 9


« Reply #13 on: February 26, 2009, 09:03:45 AM »

If a layline drawing were done for the leeward darling mark, where would that put the starboard boats when they jibe onto port to round the leeward pin in relationship to the scorers?  It seems to me that using a darling mark at the leeward end will only push more boats out toward the scorers.  We haven't seen that many collisions at the leeward mark and most of them were runner to runner after rounding where the darling mark won't have helped.  Is there really an issue at the leeward end that requires a darling mark there?

John

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ERIC ANDERSON
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« Reply #14 on: February 27, 2009, 02:23:39 PM »

John,

I can only tell you what I have observed.  At the worlds in Europe I approached the leeward mark downwind on starboard several times passing the Darling mark and gybing for the leeward mark. I don’t ever remember being close to the scorers.  My guess is when the scorers stand near position 36 they are well past the normal gybing point for the starboard tack downwind boats. 
I drew the last diagram assuming  aprox 45 deg upwind angles and 135 downwind. The windier it gets the smaller the gybe angles get but the larger the radius of the turn around the leeward mark and the longer the distance people bleed off speed before starting the turn.
All in all I don’t think the leeward darling mark would have much effect on the location of the scorers.  I also drew in a supplemental finish mark to get the sailors away from the scorers at the final lap.  I think we should implement this, but it is another thing  for the RC to carry and place. 
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sail fast,
US 5193
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