plymouth

Any idea how old this might be? We found it completely encrusted except for the jagged end. It's hard to tell whether this broke off or this is the entire spike. Pictures include multiple sides and size. The "chunk" is where the head was encrusted.

Does anyone have any experience with hunting beaches in Mass? For example the Plymouth area beaches (Long beach, White Horse Beach, even Duxbury Beach). I've read all the posted rules and regs, but nothing is definitive for MD'ing. I'm aware that any beaches that are state parks/landmarks are...