For the International Wave Class Association (IWCA), it is pretty simple. You just pay $10 to join the class association, and you will be assigned a number. I have a list of the numbers that are already taken, and the database is maintained by the class secretary. So if you have a fondness for a particular number, you can call one of us and see if that number is still available. Otherwise, we will assign you a two-digit number.

For the IWCA the number is affixed to the outside of each bow, and we try to make sure all the numbers are the same size and in the same position on all the boats, to make it as easy as possible for the race committee.

I do not know what is required in terms of numbers if you race in Hobie Class Association regattas. I would guess they would require you to put some kind of number on your sail, and they probably don't care what that number is, as long as it does not duplicate somebody else's number. Same thing might be true if you are racing your Wave in open regattas where there is not a Wave one-design class and you are racing on handicap.

If you are going to be racing in various venues, it would probably be simplest (and less confusing for race committees) if you get a number assigned by the Wave Class Assn., and then use that same number on the sail as on your bows.

I would suggest that you start all this by sending an e-mail to Rick White, who is president of the International Wave Class Association. (rick at catsailor.com) Or call him or me at 419-285-3505, which is our summer number in Ohio.

You can get more information about the IWCA by going back to our catsailor.com home page (by clicking on the Catamaran Sailor logo at top left of this page. Then open up the drop-down site index and scroll down to "Wave Class Website." (Except for the pictures on the Wave welcome page, the information on the site is pretty current, including this year's Wave race schedule.)

For the Hobie Class Association, you can probably get some guidance from Matt Bounds, editor of the Hotline. He posts frequently on these forums with the user name mbounds. Send him a private message. Ask him if he can post his answer in this thread, so other people will have the information, too.