Don't know the situation where you live. But, here in San Diego, Craig's List Free Stuff works great. Stuff that I'd think has zero value ends up going to TJ and either scavenged for parts or somehow put back in use.
I live in MI. and the best I could do was to pay a landfill to take one I had. I would run a craigslist add for free. If your boat shows even slightly well, you will get a person to haul it away for free. Is there a trailer it sits on? If yes, that alone could be the selling point if you're willing to let it go with the boat.
If it's on a trailer, leave it by the side of the road, unattended, with a "for sale" sign on it. It it's free, nobody will want it. If it's for sale, somebody may steal it.
