A video recorded the shocking scene of a shark devouring a seal very close to a Nantucket beach on Sunday. The water turned red with blood, causing authorities to ban swimming for the remainder of the afternoon.

The disturbing attack was captured in a video obtained by Nantucket Current, revealing fins violently moving in the water just off the coast of Great Point beach.

Suddenly, a shark’s dorsal fin emerges in a crimson pool, and the remains of the seal bob up momentarily before the shark resumes its assault.

“Oh my gosh, that shark just ate that seal,” the woman filming, Sandy Fink, exclaimed in the clip.

Fink, an Orlando resident who was vacationing on the Massachusetts island with her boyfriend, said she was enjoying the day at the beach when she spotted the shark.

“He was fishing along the shore and I was videotaping the seals and I was like ‘Is that blood? Wait! That is a shark and he is eating the seal’,” Fink told the Current.

Her boyfriend, Ron Welter, was about to go for a dip before she stopped him.

“Then I ran to show Ron the video and he was like ‘I was just about to go in real quick to cool off’ and I said ‘No!’”

The too-close-for-comfort attack was just one of several shark-on-seal killings reported along the eastern shoreline of the island Sunday, Diane Lang, of the Trustees of Reservations, told the local outlet.

The Trustees, who own and operate the Coskata-Coatue Wildlife Refuge which includes Great Point beach, barred swimming for the rest of the afternoon following the reports.

The organization closed the beach to swimmers last year as well following numerous shark sightings.

The seal population around Nantucket has risen in recent years, making shark sightings increasingly common during the summer as the predators help themselves to the buffet, according to the Current.