This says nothing about your generic beach cat only those that made the list. The one design list,the Uber list!
Progressive knew what a Nacra F18 was a year and a half ago (it had not been around in the U.S. very long). State Farm knew what a Nacra 6.0NA is. Even if it's an off beat boat, they'll be glad to find something similar and use it to set up you a policy. It's inexpensive and very worthwhile.
Darryl,
It's not really any more complicated. What's confusing is that most home insurance policies cover the home owner for being a dumb butt away from the home...i.e. you get a certain amount of liability insurance - some policies even specify a limitation on the boat. My homeowner's policy has a blurb about covering so much liability on a non-powered boat under 21' as an added bonus but it stopped by indicating that it would not cover power boats. If you contact an insurance company to purchase insurance for your boat, it's very much like setting up a policy for a car (and yes, using the same forms!)

.