WELLFLEET, Mass. (WHDH) — Nearly 100 beach goers spotted a shark fin above the water around one o’clock Monday afternoon at Marconi Beach between Wellfleet and Eastham.

“Dorsal fin, black dorsal fin about that shape…How big was it out of the water? It looked like it was short out of the water and I couldn’t tell out of the shadow how big it was,” said Glenn Tircarico, who was visiting from Connecticut.

The shark was no more than 30 yards offshore and officials said it moved north along the beach for about ten minutes, staying on top of the water the entire time. That sort of behavior is similar to a basking shark, but the Chief Ranger wants local scientists to see it before they know for sure.

“I hope to know soon. Members of the public were able to take photographs and one member of the public is supposed to be emailing me a picture of a fin,” said Chief Ranger Leslie Reynolds of the Cape Cod National Seashore.

Signs warned swimmers that great whites do live here. Marconi Beach and other beaches in Wellfleet were closed to swimming for about an hour.

“As soon as the lifeguard saw it, couple blows on the whistle, they were chasing everybody out of the water,” said Tircarico.

But some beach goers said they weren’t afraid.

“We weren’t too scared. The boys know there’s sharks in the water. If the lifeguard says no one go in the water, we don’t go in the water,” said Sebastian Borgognan who was visiting from Montreal.

The Chief Ranger said she is going to share the photo of the shark fin with local shark scientists on Tuesday.

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