Shark sighting prompts closure of Duxbury beach ← Related Article Visit The Boston Globe Share on Twitter Share on Facebook Comment on this Scroll to top of page Mass. State Police Beachgoers left a message in the sand in Duxbury. Mass. State Police Beachgoers were pulled out of the water this afternoon when a shark was spotted off Duxbury. Mass. State Police The shark was spotted by a State Police helicopter on the ocean side of Duxbury Beach. Mass. State Police A Duxbury fire official said State Police believed the shark was a great white.