I've made a good many skirts, have started trying neoprene since we last talked about this here. IMO, Judy's suggestions are right on the mark. Here are a few additional suggestions:

You probably already have a sizing pattern for your sprayskirt. Use the coaming pattern that came with your plans and add 2" all around for the overlap and hem.

Place the body hole where Judy suggested--4" forward--unless you've found you sit way forward or back in the cockpit.

With neoprene, size the "body hole" for a little (1") larger than your waist. Make the tube about the length of the measurement from the back of your coaming to a line that would be just under your boobies, and an inch bigger around (if you had boobies...and yes, I just said "boobies"...c'mon, I got little kids). You can add an extra inch to become a tube for elastic, thin bungee or a string and cordlock. You can simply leave the top raw, since neoprene has stretch. Suspenders (in the form of wide elastic) are nifty sometimes too; size them once you finish the rest. I put a web belt with a fastex buckle at the natural waistline to allow a tigh cinch to keep water out if I'm playing in surf or rolling. You may have to taper the tube for your body one way or another, based on your build. You want the top snug, the bottom hole can be rather loose.

You do the same for Nylon as Judy said, just allow for the lack of stretch and adjust for your cockpit as you go. Size the body with the hole about 2" larger than your *hips* (the largest area the skirt has to make it over), even more if you wear really heavy clothes. Make the tube straight and put elastic/bungee in the top, and a cinch belt at the waist.

In either case, draw an oval with a circumference that is the measurement you took earlier, about 6" thick often works (you may be thicker than I am, but I doubt it. :-, cut it, stitch the hem on the cover and make a tube from the body piece, then attach the body to the cover.

Stitch a loop of webbing to the very front, so you can do an emergency exit easily. Run the bungee through your cover hem, sit in the boat and try it for size. Make adjustments as needed, and mark where the belt and top hem go, if applicable.

Seal the seams if you're stitching, check the seal if you're gluing neoprene. The fabric may be waterproof, but the seams aren't. Seamseal from a camping store will work, as will 2 million other things.

Fun things: Add a pocket to the body tube. Just sew on a square of material, velcro on top optional.

While you're cutting the cockpit cover part, make another that you don't cut a body hole out of. Put in bungee, and you've got a travel cover for your cockpit. You can use only water-resistant material for this if you carry and store your boat upside down.

Use contrasting colors for body/cockpit.

Put a thin support (aluminum, or a thin fiberglass rod--broken tent pole, Mark-- would work)about halfway between you and the front of the coaming. It should be about 1/2" less than the width. Hold it in with a narrow strip of material. Now waves don't break the skirt loose as easily.

Put black lace around the edges. Much sexier.

Wynne