I see this is an old thread, but I'm an old man...LOL.. I wanted to add something real quick, since I read the idea of using "2" anchors. Never anchor the front and back of boat, unless your in protected water, such as a small lake. The boat should always be able to move, keeping the bow in the wind. If you anchor the front and back, then your setting yourself up to take water on from the back of the boat, with shifting winds, possibly swamping.
Also, I kept reading to see when the "chain" was going to be mentioned. There is a formula for how much chain to rope your suppose to use, to hold the anchor's position, but with skis and jetboats, I don't think it's that important. As it was pointed out, the chain basically ensures the anchor digs itself into the bottom. When you anchor, the depth, line and degree you anchor, is key to keep your boat still. I believe, when you toss your anchor in, it's supposed to have a 15 to 20 degree angle, for maximum holding power... But, I think, with our lightweight boats/skis, it's overkill.