US1M Mistral deck layout

I’ve been working on my US1M mistral, and I had a few things that I can’t find in the construction guide or in the plans. First, where should I plan to put the holes for the lines to exit that control the sails? (These are called sheets, right?) I would guess that they are obviously on the centerline with regard to port/starboard location, but where should I put them fore and aft?

Second, I want to be able to adjust things to suit changing conditions, but I’m not sure of exactly what to expect. I figured I would make the mast location and thus the jib pivot and attachment point for the side stays adjustable. How much adjustment should I build into the adjustable things? If I made 3 different holes to step the mast with 1/2" center to center distance, would that be enough adjustment? Would anyone suggest a different number of holes and/or a different spacing?

I figured out some locations for the jib attachment point thanks to the guide, but how much adjustment should I have fore and aft for it? Should it just match the mast to allow for a 3/8" slot between the main and jib? Or, should I make say, 1/4" inch adjustments?

What about the side stays?

Finally, how far aft on the main boom should the vang attachment be?

If anyone can help me with details of their boats, further reading, and/or whether any of these items really even need to be adjustable, I would appreciate it.

For pictures of the hull building process, see

I use a Deck Track from GBMY
You can adjust anything anywere.
See picture.

Download Attachment: CF4.jpg

Download Attachment: CF2.JPG

If It Don’t Float Add More Foam

I have built 5 Mistrals and for some reason mine seem to want the mast farther forward than anyone elses. It wants to be about 18" from the bow. I don’t know what causes this. Because I have had this discrepancy I would reccommend that you build in as much adjustment as possible (within reason). If you can, make the adjustment temporary and then when you know where the boat sails for your conditions you can make the positions permanent. This usually means building in a little more deck reinforcement for moving things, especially where the chain plates attach. Just make it so,if you have to, you can move the chain plates ahead an inch or so. I have the vang attachment about 4 1/2" back from the mast. I don’t think it’s critical. The size of you fingers would enter into this decision. If you want more specific stuff I can measure it for you.

Don Case
Vancouver Island

P.S. If you go to this link there is lots of stuff that will help. If you didn’t know a ODOM is a Mistral.

Wow, I didn’t know that an ODOM was actually a mistral… thanks. Thanks too for the tips! What about keel bulbs? The amya plans call for 5 pounds… does that sound like a good starting point?

Build the bulb last. The Mistral was designed for around 7.5 lbs apparently so after the boat is finished and assembled (rig and gear included),weigh the boat and and determine what the bulb weight should be. Another thing you can do is float the complete(less bulb) boat and pile tire weights(or something) on the deck until the boat is floating on the design waterline. Weigh the tire weights and that is your bulb weight. Mine run about 4.5 lbs which probably means that the rest of the boat is a little heavy.
If anyone else is reading this and I am giving bad advise please chime in but this has all worked for me.

Don Case
 Vancouver Island

so far so good don. nothing i see wrong
the only thing i would suggest is sticking to a 5 lb bulb . for your first boat. i dont want to say you are going to be a world beater the frist time out. but lets be real and lets have fun. 1/2 lb for you first boat is not unreal and the benefits will out wieght the cost. it will give you a stiffer boat. and you wont have to worry so much about wind conditions
good luck and welcome

long live the cup and cris dickson