Preliminary Template

So I am still without a job and get super bored so yesterday I cut out some templates of a hull I designed on I-Deas. Not sure about any of the chracteristics, more just for fun and to take up time. Here are some pics that i set up before I fully committed and built a real building board with wood and all. Provides a solid visual though.

Download Attachment: [ small temp.JPG]( temp.JPG)

Download Attachment: [ small temp 2.JPG]( temp 2.JPG)

Download Attachment: [ small temp 3.JPG]( temp 3.JPG)

I might be going way out of my league here, but here I go:

I’ve grown up with the idea of sailboats being smooth below the water line. Isn’t the transition from the sides to the bottom too sharp in the aft half?

When heeled, won’t the “corner” cause more drag than a more rounded transition?

I had NO education on boat design BTW.

Besides that, I like the overall shape of that hull, makes mine looks overweight!


The more I practice, the luckiest I get.

I still have some fine tuning to do on the templates, namely smoothing the corners. You bring up a good point and this design was made by me going on a bunch of current modern maxi yachts there is a human error factor. Whats hard to tell in the picture is where the water line is, the stern will be out of the water for the last 3 or so inches so when it is heeled it will be in contact but not as much as you may think deending on where you were expecting the waterline to be. Thanks for the input.
Andrew Miller

hard to tell without any reference dimensions but . . .

You sure there is enough volume? It looks a little light. . . but im not sure what “class” you are aiming for. A little more information would be helpful (length, beam, displacement, rocker etc). One thing to keep in mind is that volume and displacement do NOT scale 1:1 like length dimensions.

I too design in SDRC I-deas. Do you have access to flow-therm? there are some neat tricks where you can get flow therm to act as a tow tank. Gets you atlease 90 of a good VPP. Espeically if you start to iterate designs.


First off, I do not have access to I-Deas anymore so that isnt possible. Quick question, when you say light? Do you mean its going to float too high or too low? I am confused by your references to light and volume. It is 44" long, max beam is just over 8 inches, the max beam occurs at 26 inches from the first bow template and the rocker is 1.25" inches assuming you are talking about the max depth of the hull from the waterline? I am not that familiar with that term though. Thanks for all the input.
Andrew Miller

sorry for the confusion.

Yes, light, as in it does not have enough volume for the displacement I would have expected for a boat of its size. What is the anticipated displacement? Did you have I-deas calculate it for you?

and yes, the max rocker is the maximum depth as measured from the waterline.

Im on my 3rd or 4th iteration of a design . . . and the only thing I would encourage you to do is to avoid straight lines, such as in your U shaped bow. adding a small amount of curvature will make it much stiffer without having to use a beefy laminate schedule to achieve a sound hull. Try using elliptical sections, or parobolic sections. I learmed this the hard way. My first US one meter was similar to what you are working on (but much narrower). The flat sections cursed the design!


The forward section of the boat (about to the mast) is going to reinforced with the plywood templates that i make for planking. Having never planked a hull that will actually be used for sailing will that be enough, the bulkheads are 3 inches apart. Also all the corners will be smoothed off on the final templates allwoing for a smoother hull and transitions from the different surfaces. Seeing that I am not designing for a specific class, I have no restrictions on displacement and therefore can experiment with bulb weight and length of keel. thanks for the help.