Preview: Scribing & Maintaining a Waterline, With a Batten and a Pull-Saw

17 Responses So Far to “Scribing & Maintaining a Waterline, With a Batten and a Pull-Saw”

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  John Wujack says:

  With regards to waterline optics…..I’m aware of the practice of a fairing a slight ascending curve near the bow for appearance sake. I would like to greatly reduce the width of the bootstripe on my Stone Horse and it leaves me wondering…….should only the top edge be faired upward while maintaining a horizontal bottom edge or should both the top AND the bottom edge of the bootstripe sweep upwards? Thanks, John

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  Ian Latham says:

  Just another comment, on a similar topic: “The boat floated on its lines.” How does that happen? Does the designer or the builder know where the waterline will be? How do they know? And do they hit it every time? If they don’t, what happens next?

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    Maynard Bray says:

    The weight of a boat (or any floating object) equals the weight of the water it displaces. So after a designer calculates or estimates a boat’s weight and its location, he or she can figure out how deeply it will float and where the waterline should be painted. Since sea water weighs 64 pounds per cubic foot, a boat has to be less dense than this or it won’t float. This is a pretty brief description, but any book on yacht design will cover the subject in more detail, if you’re interested.

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      Ian Latham says:

      Thank you for the explanation. Now I have an understanding, I will indeed look further. It fascinates me. Much appreciated.

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      Ian Latham says:

      Just ordered Cyrus Hamlin’s Preliminary Design of Boats and Ships, which, as the reviews suggest, should repay study (!) Thanks for the encouragement.

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  Ian Latham says:

  I knew about the kerf and what it meant. But thanks to Mr. Hawkins, now I know how to use it. A very helpful video. Thank you.

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  Brian Ellingson says:

  You cannot go wrong with good advice from a somebody that knows what they are talking about.

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  Jerry Stavola says:

  I like this idea and will be doing it next spring when I refinish the hull…we’re cruising now

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  Mark Ritter says:

  Thanks for the advice! I’ll be stripping, recaulking and repainting my first traditional carvel boat soon, a Fenwick Williams Catboat and I’ll certainly use this technique.

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  Peter Jackson says:

  As always with Havilah, well-presented useful advice.

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  Jeff Davis says:

  Great video. When I finished my CLC kayak, I used a steel measuring tape securely fastened at each end of the hull as an edge to scribe the waterline. That gave me a fair line with no whoop-de-doos for masking. My hull is blue with about an inch of red from the sheer down separated by a white stripe (naturally). By the time I reached the white stripe stage I was so tired of masking that my friend who stripes cars for a living suggested that I use whatever width of automotive striping I liked. Perfect!
  I really like Havilah’s solution to a permanent waterline. I am always amazed at boat builders simple inspired ideas for problem solving.

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  Steve S - RestHarrow Boatworks says:

  Another great video!! The finished boat looks fantastic.

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  Michael Jolicoeur says:

  I’m more of a Louis Sauzede fan when it comes to waterline determination & placement. Can’t understand why scoring the hull is beneficial.

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    Andy Reynolds says:

    This technique is as much about the painting as it is about the marking. And repainting being an annual ritual, for those who care a lot about the way their boat looks, efficiency becomes more important. So, not having to relocate and remark every year, and not having to mask to get that line sharp and accurate seems like a great way to increase efficiency and spend more time on the water, and not on the hard. This really only applies to carvel planked boats, doing this to a hull thats epoxied or especially, glassed, is obviously not a good idea. In context, this seems like a great technique.

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  John Franks says:

  Thank you once again for a great video.

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  Tom Sliter says:

  Another great video from an obvious craftsman. Are there any tips for applying this technique to a lapstrake hull where the kerf has to cross the planks?

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    Weaver Lilley says:

    Yes, more complicated on a lapstrake hull where the waterline must zig & zag between strakes to be accurate and appear straight when viewed level on. On my Caledonia Yawl, the strakes are 3/8″ plywood. Cutting into the veneer layer made no sense so I scored it with an old awl held at an angle.
    I used the old carpenter’s level trick to draw the waterline. A quart container of water darkened with blue food color and a clear 12′ neoprene tube siphoned to a waterline mark from the plans. When you adjust the height of the container to bring the colored water in the tubing to the mark, you can move the tubing all around the hull marking every 6″.