Find out the law in Delaware. Take a month in Florida working on the boat and leave. I'd suggest going directly to the Bahamas (out of the country) hang out for maybe 45 days and then bring it to Delaware.

That may do it if the law in Delaware is 90 days. You could use the money you would have paid on sales tax to fix the boat up and cruise.

You have to be tricky, they don't want you to get away with it. Know the rules and use them.