"Anyone tries to get in the water, they’ll be taken right out of the water," he told reporters.
The mayor said that city officials would not put up police barriers at beaches, giving New Yorkers the chance to comply voluntarily. Swimming, lifeguards, parties, barbecues and sports would all be prohibited on the beaches, de Blasio added, and social-distancing rules will still apply.
"It's a dangerous situation to ever go in the water if there are no lifeguards present," he added, saying officials are also concerned about scenarios where large numbers of people take the bus or subway to beaches. Only residents of the communities surrounding the beaches would be allowed to use the beach as “just open space you can walk on,” he said.