Duxbury Beach was closed Friday afternoon after a reported shark sighting, officials said.
Around 1:20 p.m., a boater reported to Duxbury's Harbormaster that he had spotted a juvenile great white shark about 150 yards offshore feeding on schools of fish.
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Forty minutes later, Duxbury Beach Operations tweeted that the beach was shut down due to an "unconfirmed" shark sighting near the shoreline.
Officials said the beach would be closed to the public for an hour, however the beach was reopened shortly after the initial announcement.
Boaters who grew up in the area were not surprised, but said they are concerned about great whites making more frequent visits to the nearby waters.
"It doesn't make me feel good," said Tripp Neville of Duxbury. "[Scuba] diving I think is probably coming [to] an end…I don’t know, makes me feel a little uncomfortable."
On Monday shark biologist Greg Skomal spotted nine great whites off Wellfleet Harbor – the first time he’d seen them inside Cape Cod Bay. Duxbury is just across the bay, about 30 miles away – not too far for a great white known to travel dozens of miles a day to find food.