Thanks Ellen and Roger for the information.
I will save my money, so that I can buy some new sails.
As to the question why I have a tendency to sail underpowered. One is thinking the wind is stronger than it is. The other is that when I was first learning how to get into the harness I took a very bad spill. It was bad enough that Andrea and another person ask me if I was alright. Also, during that time a did a couple of catapults. What can I do to get over this fear of going so fast that I am out of control.
Also, is there a limitation for what sails I can use on the F2 Phoenix 340.