Scientists are warning beachgoers that massive sharks are lurking in the water near Cape Cod, Massachusetts.

“Just know that large sharks are here,” said Megan Winton, a researcher for the Atlantic White Shark Conservancy. “They’re a constant presence from June to the fall.”

Winton’s warning came one day after a great white shark was spotted at Head of the Meadow Beach in Truro, MA, prompting officials to close the shoreline for an hour.

Grek Skomal of the Massachusetts Division of Marine Fisheries says that the great white sharks are mainly focused on the area of Cape Cod that faces the Atlantic Ocean due to the seal population.

“Sharks will come close to the shore when they have water depth,” Skomal said.

The Atlantic White Shark Conservancy notes that the only way to avoid sharks is to stay out of the water.