From April to November, the
www.pemivalleyhabitat.org/restore.htm in Plymouth always has a couple to three different boats parked in their large parking lot, for sale, which had to be donated. Usually, it's smaller boats, 12-18', like sailboats, canoes, rowboats.
ReStore Plymouth has a large box truck with crew for removing large refrigerators so maybe they could haul a boat away?
In Meredith, the Hearts and Hands Thrift Shop on Maple St, close to AJ's Fishing store, will take your smaller boat, like a sailboat, canoe, rowboat, probably a small motorboat on a trailer. There's a loading zone directly out front, and they/you/volunteers move the boat onto their front grassy lawn there, for display. Hearts and Hands is a thrift affiliated with three local churches.