Humarock Beach closed around noon after the shark sighting was reported.
The first great white shark of the year has been spotted off the coast of Massachusetts.
The harbormaster today advised beachgoers that if they do go in the water “they should do so cautiously and avoid going into the water beyond waist depth.”
A state police helicopter spotted the shark in the area of the Powder Point Bridge.
A reported shark sighting in Weymouth prompted lifeguards to order swimmers out of the water at Lane Beach on Thursday.
A reported shark sighting that cleared three beaches in Nantucket on Wednesday was not a shark after all.