News to me. And I live in FL.
I think he's referring to the Sojourner's Permit. If you're registered in another state, you may normally stay in Florida without registering for 90 days. You may then register for an additional period of time if you do intend to take your vessel back to your home state.
http://www.paradiseyachtsales.net/wp-content/uploads/2014/01/Sojourner1.pdf