Latest News: Forums Technical Offsets

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  • #3932
    Anonymous
    Inactive

    Can someone please let me know the offsets from gunwale to waterline for a woodie, please?

    Thanks

    Charles

    #8198
    Swiebertje
    Participant

    I don’t know the answer to that, but what I did on my old boat was use one of those cheap laser spirit levels on a tripod, like this one:

    1. Level the boat on its trolley or trailer, length-wise as well as across.
    2. Find at least one spot of the waterline you are sure about.
    3. Adjust the tripod’s height until the laser points at the waterline spot and the spirit is leveled in all directions.
    4. Mark the waterline on the hull by turning the laser spirit level.
    5. Repeat the process on the other side of the hull.

    I got my laser spirit level and tripod for about 15 pounds (actually 19,95 euro) from Lidl. It may not be the best professional quality money can buy, but it sure is good enough to do this job.

    By the way, the shorties Lidl offers are perhaps not the best fit but they are good value for money, as well as their waterproof binoculars with build in compass and compass lighting. Just visit their site regularly for good sailing bargains. Only yesterday I saw some nice looking hiking boots and water resistant sandals on their web site.

    BTW2: The tripod is also good for making panoramic pictures.

    #8199
    Anonymous
    Inactive

    Thanks for that. I have a laser level already, but I would need to know which bits of the boat are level fore-and-aft when the boat is level. I would reckon on either the rear deck or the top of the centreboard case, but it would be handy to have this confirmed.

    #8204
    Swiebertje
    Participant

    The transom and the bulkheads should be plumb. I am not sure about the various GRP types but in a woody the the top of the CB is lower near the mast then it is near the thwart, not even the floorboards and the benches are level. According to the official drawing of a woody, the floorboards slant slightly down towards the mast and the benches up (?!?). The benches are almost level though. The waterline in the official drawing, just touches the bottom of the keel at the transom.

    #8206
    Anonymous
    Inactive

    Thanks again for the info. Now I know which of the two “waterlines” on the Mk IVs pictured in the latest W News is the one to go for. Perhaps they are the “laden” and “unladen” waterlines! Also looking at pictures of empty Ws shows the transom to be just clear of the water, so the “official” waterline appears to be the “unladen” one, though it depends, I suppose, where the crew are sitting.

    #8209
    Swiebertje
    Participant

    Often yachts have a false waterline. This is basically the real waterline but the ends near the bow and transom are slightly lifted. This gives the boat a more slender and “fast” look. Fishing cutters (both classic and modern) took this to the extreme by having a white triangle between the real and false waterline at the bow. The white triangle is about where the white foam “moustache” will be when the boat is at speed.

    I don’t think it would be a good idea to raise the waterline at the transom of a Wayfarer but raising it at the bow may give your boat a better appearance. The Wayfarer is after all a typical English design. Since the English don’t have much inshore sailing waters most English boats are designed to behave well in a chop. Such designs typically have lots of volume in the front part of the boat. The Wayfarer is no exception and has, like a fishing cutter, a pronounced bow. Fooling around with some masking tape will tell you if I am right or not.

    #8210
    Fantasia
    Member

    I have my boat at work at the moment, due to an unintentional modification to the mast last weekend (now in two pieces), so I just took this image to illustrate my waterline. If it has uploaded you will notice that the line starts approx. where the lower chine meets the bow. I could take some measurements at other points if you like.

    #8211
    Fantasia
    Member

    Help. I do not seem to have uploaded my image. Do I need to re-size it before loading? What else might I be doing wrong?

    #8212
    Fantasia
    Member

    Let’s try again, I’ve reduced the size.

    #8215
    Swiebertje
    Participant

    A perfect example of a false water line. According to the drawing the real waterline is some 2 or 3 inch lower at the bow. And if I hold a straight line (the edge of a piece of paper) against my screen it also shows the waterline is lifted at the bow. The boat does look so much better this way. I guess the lifting starts a little in front of the trailer wheels.

    A very nice paint job by the way, with the fading blue’s.

    #8288
    Swiebertje
    Participant

    It took me a while to trace the data requested, I knew it was out there somewhere. I was unable to find the original W-news article but by a stroke of pure luck the data appeared in a summary of the original article in the latest issue of W-nyt, the Danish W-news. With a little help from the Danish author of the summary, it is now available in English (Actually its Danglish):

    http://www.wayfarer-international.org/WIT/maint.repair.ref/BoatPreparation/WayfarerWaterLine.pdf

    Please note that the bottom edge of the water line in the drawing is already a false waterline, lifted slightly at the bow and stern. The real water line is exactly level (obvious) and below the drawn lower edge, it touches the bottom edge of the drawn line in the middle section of the boat. Obviously we are talking about a waterline of an empty boat with the minimum allowed hull weight.

    Because the summary was a reprint of an older article the original English text was lost in time years ago. Perhaps someone reading this still has a copy of the original article available? If so, please let me know.

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