...and you should have one....
You can easily make an anchor riding sail. Take an old hank-on sail (or just buy a cheap one from a broker)and cut the sail so that you have about 3 hanks worth of luff. (If you plan this carefully, you'll be able to make a number of anchor riding sails and give them to your friends.) Hanks are typically about 15-18 inches apart -- you do the math. Fold the cut edges to form a triangle and then sew them down. Press in a cringle and bingo, almost instant riding sail. While you recently commented about "size being important" elsewhere, the key is not so much size, but how you use it....*pop