Memorial Day diners at a popular seaside restaurant on Block Island were treated to more than just seafood this week, they witnessed a massive 20-foot shark gliding through the calm waters of Great Salt Pond, just feet away from a small boat.The startling scene was captured on video by local resident Jen Seebeck, who was eating at Dead Eye Dicks, a waterfront restaurant overlooking the pond. The footage shows the shark’s enormous dorsal and tail fins cutting through the surface as onlookers gasp. At least one person can be heard shouting the now-iconic phrase from the 1975 film Jaws, “There’s a shark in the pond!”The Atlantic Shark Institute, which reported the sighting, said the shark’s species has not yet been identified, but estimated its length to be around 20 feet. The sighting instantly evoked comparisons to the legendary movie, which is celebrating its 50th anniversary this year.Close call on calm watersA small boat was seen cautiously motoring away from the powerful predator as it swam through the pond, which connects to the open ocean. Though sharks occasionally make their way into shallow or enclosed waters, the presence of such a large specimen in the small, tourist-frequented Great Salt Pond is rare and unsettling.“Sharks are arriving in Rhode Island daily as water temperatures continue to rise and more and more species of shark find them suitable to their liking,” the Atlantic Shark Institute wrote in a social media post. “Hopefully this shark will find its way out of Great Salt Pond soon and continue on its way!”Shark season beginsMarine experts say the sighting, while dramatic, is not entirely out of the ordinary. As waters warm up along the Northeast coast, various shark species, including Great Whites, migrate closer to shore in search of food. Montauk, New York, just across the water, has already reported a large Great White shark sighting earlier this month via drone footage.“This is consistent with seasonal behaviour,” marine biologists noted. “As fish and other prey move closer to shore during the summer months, sharks naturally follow.”