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  1. #1
    Join Date
    Aug 2019
    Posts
    13

    Default Tools for Setting Marks for Yacht Races

    I have developed a New Free WebApp tool to help race officers set up the marks for yacht races. You simply enter the wind direction and the windward leg length, and the tool provides the bearings and back- bearings for all Marks => for Both Triangle and Trapezoid courses. Another option provides lat/longs for all Marks after the user clicks a Geolocation button at the bottom mark as the reference point. No more fiddly tables.
    I would like to get some feed-back on it.

    See

    https://www.setcourses.com

    some examples

    Simple Triangle 60-60-60 =>

    https://www.setcourses.com/triangle60.html

    Triangle Lat/Long

    http://www.setcourses.com/triangle_latlong.html

    Trapezoid Lat/Long =>

    http://www.setcourses.com/trapezoid_latlong.html

    Cheers

    John


  2. #2
    Join Date
    May 2007
    Posts
    38,125

    Default Re: Tools for Setting Marks for Yacht Races

    1) Lat/long format could be more usefully DDD MM.nn?

    Different RO's seem to use different reference points, either the windward mark, committee boat, centre of start line etc.
    The question being, what do you try to keep constant if the wind changes?
    It's crucial IMHO to be able to move the windaward mark after the first beat, but also handy to be able to move the leeward end.
    Often you want to keep the committee boat fixed as a reference, but OTOH, we often move it to the finish line.

    In our world the wind is only used in units of 5deg, and we can add 55, 60 or 65 degrees in our heads to put the gybe mark in, and subtract to get the bearing from the leeward mark.

    You might want to consider the ugly option of marks to starboard, it can be necessary.

  3. #3
    Join Date
    Aug 2019
    Posts
    13

    Default Re: Tools for Setting Marks for Yacht Races

    Thanks for your response.
    1. I will look at change in lat/long format as an option.

    2. Generally we keep the bottom mark as a fixed reference. The setcourse tool works on the bottom mark as reference (3 for triangle; 4 for trapezoid). To make adjustments all that is needed is the new lat/long for these marks => that can be provided by the boat that drops the mark using GPS or the tool's Geolocation button. This can be radioed to the other boats. All the course setters can adjust their setcourse tools for the change in the reference point providing a new set of bearings and lat/longs.

    3. If the wind changes and the other Marks (1, 2, (3)) need to be moved, the setcourses tool can be adjusted by simply entering the new wind direction => revisedset of new bearings and lat/longs.
    For regattas we have three boats for management. If the race officer (RO) decides there needs to be a course change for a Triangle course, due to a wind shift, he radios the new upwind bearing. All three boats adjust their setcourses tool settings. Boat1 moves the upwind mark using the new back bearing and RO checks the bearing => 'drop'. Boat2 moves the wing mark using the new bearings. RO and Boat1 check => 'drop'. We use bearings rather than lat/longs as we only have 2 GPS units (!!) and changing lat/longs is fiddly. Our RO generally relies on Boat1 and Boat2 to set the buoys, after announcing the new upwind bearing => delegation! In our experience mental arithmetic fails and causes endless confusion.

    4. Setcourses has options for Triangle - starboard. Trapezoid starboard could be done if there is a need for it.

    Cheers and Best Wishes

  4. #4
    Join Date
    Feb 2004
    Location
    Boat (now back in) the Clyde
    Posts
    5,640

    Default Re: Tools for Setting Marks for Yacht Races

    Scottish National Sailing Centre at Cumbrae helped develop methods for setting positions for race marks, as well as other techniques, which was developed into a useful U.K. wide (and RYA?) mark Layers Course (used for some big events, poss including 2012 Olympics?)
    Not attended so not fully familiar, but if your app is complementary to their techniques that sounds great. If duplicates then perhaps less so. Have you investigated this?

  5. #5
    Join Date
    Aug 2019
    Posts
    13

    Default Re: Tools for Setting Marks for Yacht Races

    Thanks for the feedback
    I googled and found reference to RYA Mark layers courses. (2 days wow!). I could not find any reference to tools for getting bearings and lat/longs. If anyone knows of such tools that they use let me know (thanks).
    This link summarises what is in the courses.
    http://www.abclubhk.com/upload/Cours...ng-Courses.pdf

  6. #6
    Join Date
    Aug 2019
    Posts
    13

    Default Re: Tools for Setting Marks for Yacht Races

    I found this set of notes based on RYA course setter - Looks like they use tables for mark bearings! Great set of instructions. Cheers

    see http://www.yotter.co.uk/Club%20Markl...se%20Notes.pdf

  7. #7
    Join Date
    Aug 2019
    Posts
    13

    Default Simple Ways to Estimate Distances Between Marks

    Any ideas for simple ways to measure distances when laying marks?
    => Man-over-board can be used if you have a GPS
    => Golf range finders do not go far enough (<800m)
    => Binoculars exist with inbuilt compass and reticule but they are very expensive
    Any other suggestions?

  8. #8
    Join Date
    Mar 2003
    Location
    s e wales
    Posts
    17,566

    Default Re: Simple Ways to Estimate Distances Between Marks

    you put the starting point into the gps as a waypoint and then at the potential mark you ask the gps the distance to the waypoint.
    this post is a personal opinion, and you should not base your actions on it.

  9. #9
    Join Date
    May 2007
    Posts
    38,125

    Default Re: Simple Ways to Estimate Distances Between Marks

    Steam for n minutes at x knots....
    Chartwork.
    Vertical angle of a known height, e.g. a yacht mast.
    Radar.

    If we need to be accurate, we use GPS.

  10. #10
    Join Date
    May 2007
    Posts
    38,125

    Default Re: Tools for Setting Marks for Yacht Races

    I was at a dinghy event recently.
    No less than 5 mark laying boats, plus committee boat.
    A good operation is all about getting a course in very quickly if needed, usually after a period of monitoring the wind.
    Any technology used must be suitable for a 4m RIB laying marks in F6. i.e. it can be wetter than scuba diving.
    Also comms frequently play up on such boats, even along fairly built up bits of coast.
    Laminated tables of bearings are reliable technology. IP88 and no batteries required.

    But peole need to use their judgement. All the formulaic stuff falls apart when the True Wind is different at each mark.

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