I contacted J/Boats and obtained the following in an email from Kendra Muenter.
Hi Bill;
We're pleased to have the J/30 Class be able to reproduce the logo for class flags, decals and general class web and print use. The only restriction we have is in merchandise (T-Shirts, Hats, etc...) as we have a licensed company for those items.

Let me know if you need the logo and if you need any contacts for flags and decals, as we have worked with several companies, both local and international.