I was going to make a nylon spray skirt, and then I found one that cost about $20 after shipping from Sierra Trading Post, and I got that instead. In the meantime, the neoprene skirt I was using just fell apart one day, so I'm making a neoprene spray skirt from an old wetsuit. The wetsuit was provided by Peter at the Cal Sailing Club (after I posted a wanted ad on the Freecycle mailing list).
What you see in the above photo is the forward portion of the spray skirt. It's made from the front of the wetsuit and includes the zipper. Some of the edges have been glued to hold the shock cord that will hold the skirt in place.
The second photo shows the aft portion of the skirt, prior to being trimmed and glued for the shock cord. Packing tape is going to be used to hold everything in place while the glue dries. I'm using Aquaseal instead of neoprene cement because I already had the Aquaseal.
The two parts of the spray skirt are going to be trimmed and glued together. Then I'm going to have to figure out how to finish the top of the torso part - maybe with shock cord or a drawstring, or I might roll the edge and glue it to itself to make it more durable.