Home Forums Club Development Racing mark positions

This topic contains 7 replies, has 4 voices, and was last updated by  Christopher J Harris 6 years, 1 month ago.

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  • #2913

    Jon Edwards
    Moderator

    After many years with the race marks in the same positions, they were moved as a trial during the Frostbite open series, based on analysis of the wind direction during club racing over the last 2 years. This is an attempt to improve the positioning of the marks to better suit courses that can be set for the predominantly NW / SE winds experienced, but also taking in to account the other wind directions.

    See here for more detail.

    What do you think? Has this improved the racing? Should this be a permanent change from the new season?

    #2937

    It’s fine and logical. What complaints have arisen are due to the need for more publicity before the first event (the old layout was still on the website) and the leaning markers which meant 3, 6, 8 and 9 could look alike. There is need to take more account of shallow water between 3 and 4.

    #2943

    Jon Edwards
    Moderator

    The trial change was publicised on the website prior to the first event (published 16th October) and there were also posters in the club house next to the race board explaining the change prior to the first event too. Laminated A6 cards of the new layout were also made available to all sailors to carry in their boats. It was also publicised in the October newsletter which admittedly was a bit late going out. The information was available but from the questions that I was getting asked it appears that most had not read it.

    The problem of leaning marks is something that has been with us all season since the marks were overhauled during the last winter break. There are plans to address this issue before next season. It is also intended to address issues with the length of the mooring ropes, so that the marks do not drift around due to changes in water level or wind strength and direction.

    Account of the shallow water all around the lake was considered when determining the new mark positions and a number of the marks have been moved further from the bank for this reason. The shallow water was also considered when designing the courses, to minimise the potential for boats running aground or causing incidents due to inadequate room for manoeuvre. The shallows are clearly shown on the diagrams for the new courses. However all sailors need to be aware of where the shallows are and make allowance for this when sailing. There has been an overhead view of the lake showing the position of the shallows posted on the racing noticeboard in the clubhouse for the whole of the season for this reason.

    #3032

    Dave Herbstritt
    Participant

    Some ideas/suggestions:

    1. Colour of buoys

    One of the difficulties with the markers on the lake at the moment is distinguishing adjacent marker buoys from one another along the long shores. This could be made easier by painting the buoys alternate colours.

    Suggestion would be: Even, 1 & X one colour. Odd (except 1), & Y another colour
    Colours to bear in mind those who are colour blind!

    2. Old Buoy 9 spectator sport

    Old buoy 9 supported the spectator community outside the club house – especially in strong weather as a jibe mark, with winds from the NW. It would be useful to be reinstated by moving the new ‘buoy 1’ to nearer the ‘old buoy 9’ position. Any detriment to the ideal course would be more than offset by the enjoyment it brings to non racing club members or those not fool hardy enough to go out that day.

    3. Simplify courses

    Is it really necessary to have so many buoys on a course? My suggestion would be to have 7 buoys as a maximum in the course (excluding start line buoys). I see no reason to have every direction covered in each course. Different boats will have different advantages etc, in different races . Pleasing all the people all the time can lead to over complicated courses.

    4. Accurate wind direction assessment for choosing the course

    Courses have been scheduled in the course book based on an accurate wind direction. To be able to choose the best course, the OD needs to know the true wind direction and this would be best done electronically via a more accurate wind vain or simply by a compass bearing. Does anyone know exactly where NNW wind direction comes from as opposed to NW?

    Inaccurate assessment of the wind direction leads to courses being chosen that do not serve the racing that day and therefore can affect the whole experience.

    #3038

    Good ideas Dave. Not too sure about the wind direction need for great accuracy at one chosen location as it is noticeable that the direction is often noticeably different at each end of the lake and the water-level wind direction may be quite different to that at the anemometer/flag height. Could we stick small flags on the buoys as a practical and cheap alternative? The OD could then see a ‘map’ of directions and use experience to chose the course.

    #3050

    Jon Edwards
    Moderator

    I monitored course selection verses wind direction as shown by the weather station during the season with both being noted on the results published on the website. As part of this I also evaluated the accuracy of the direction as shown by the weather station against that displayed by the boats as they sailed (beats are great for showing the wind direction as seen by the boats on the water) and against my own observations by walking around the perimeter of the lake.

    Overall allowing for the normal oscillations seen in wind direction the average direction shown on the blue trend from the weather station is a very reliable indication of the actual wind direction seen on the water, with the obvious exception of when the wind is very light i.e. When the water is glassy with little or no ripples. The raw wind direction data shown by the red crosses gives a good indication of the extent of the oscillations.

    At wind speeds below 6 knots flags on the buoys may provide some benefit, but above this the wind velocity gradient is such that above 3ft the wind velocity and direction will be pretty much identical to that shown by the weather station positioned some 20-25ft above the water level. The only factors likely to change this are local obstructions e.g. trees, bushes, buildings.

    With the exception of a few instances where the wind direction changed significantly after the course had been set, from my observations the main reasons why a course did not suit the wind direction was down to two principle reasons;
    1. The race officer didn’t use/believe the weather station and choose a course based on his own perception of the direction. Inevitably the weather station indication was correction.
    And/or;
    2. The race officer decide to make up his own course rather than using one from the book.

    #3051

    Shotwick Admin
    Keymaster

    I think sometimes there is a bit of confusion regarding the line. Sometimes it has been set up in a way that it is so wide that you can one tack the first beat, or with so much line bias (even with the correct course chosen) that makes the first beat more of a fetch.

    Something I would like clearing up, is whether the start line is a line between the Inner & Outer marks or a Transact on the Inner mark and flag mast on the trolley? Ask different people, you get different answers.

    If the later then we could put makers around the lake for where the flag trolley should be for each course, and a windex on top to the flag trolley so it can be sat at right angles to the wind (a little bit easier than fluttering flags though I may be simplifying it a little to much)

    It’s Monday morning so I may have missed a blatant point why that wouldn’t work.

    #3168

    There is a desire for slight movements for fun; e.g. have No1 nearer the clubhouse, but, more importantly, number 4 needs moving as boats are grounding even to the lake centre side of the buoy.
    Note that the club sailing plan on the website shows the old buoy positions. Not good for open events.

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