My favorite source of parts is Mariner Sails, the Dallas Hobie dealer. If you don't live near Dallas, don't worry, they'll ship parts anywhere. They have a big parts inventory and a knowlegable staff. Their site has online part diagrams that are fantastic. You can see every part for your Hobie, get part numbers, and see how much they cost. Visit them at:
http://www.mariner-sails.com/. Click on the "Hobie Cat" tab on the menu on the left side of the home page and navigate from there. Typically, if they have your part in stock, and they usually do, they'll ship the same day via UPS if you order before noon. Free shipping for military.