If you log into jibeset, and you're a member of one of the same organizations, you can click on the 'SSS Membership' or 'YRA Membership' buttons at the bottom left of the screen. Then you'll be taken to a list of all the boats that are members of SSS or YRA, respectively, sorted by sail #. On the right hand side of each row is a button that says "Contact." If you push it, Jibeset will send your contact information to the person who registered the boat.
You should have an example coming from me, just so you can see what that's like for the recipient.
It is up to the recipient to contact you.