The sky was clear over Rockaway Beach in Queens early Saturday afternoon. Lifeguards scanned the still waters, dotted by a few swimmers, and occasionally blew whistles to warn those who ventured too far into the ocean.

It was a tranquil scene along the same stretch of beach where, just days earlier, a shark bit a 65-year-old woman, alarming many New Yorkers during the height of summer.

The woman, Tatyana Koltunyuk, had been swimming alone near Beach 59th Street when she was bitten on the left leg, officials said. Lifeguards who heard her screaming for help rescued her, and she was taken to Jamaica Hospital, where she was in “serious but stable” condition as of Tuesday, the police said. The beach was closed for swimming and surfing on Tuesday.

Jose Velez, 64, was at Beach 59th Street on Saturday with his wife, brother, sister-in-law and nieces and nephews. The family comes to the beach every year, he said, and had “never, never, never” heard of such an attack.

Shark attacks are very rare, according to experts. The Rockaway Beach attack appeared to be the first confirmed shark bite in New York City waters in decades. While beachgoers seemed mostly unfazed, the encounter prompted city officials to deploy more drones, boats and helicopters to monitor the city’s beaches.

Such a mobilization to spot sharks is not new in New York State. More sightings in recent years led to increased shark patrols along more than 100 miles of Long Island beaches last year.

But the city seemed to be expanding its efforts in response to the attack on Monday. On Wednesday, officials from the city’s Parks Department, Fire Department and Police Department said they were working together to keep watch over all the city’s beaches — from 9 a.m. through dusk every day — through the end of the summer.

Every morning, before the beaches open, the agencies will fly drones above the water, while boats scan below, Joseph Pfeifer, first deputy commissioner with the Fire Department, said. The drones will also fly throughout the day, Mr. Pfeifer said.

The Police Department will monitor the waters at Rockaway Beach, Coney Island in Brooklyn, Orchard Beach in the Bronx, and South Beach in Staten Island, said Inspector Frank DiGiacomo, the commanding officer of the department’s Technical Assistance Response Unit, at a separate news conference on Friday. If a shark is spotted, the agencies will not necessarily shut down an entire beach but will close it to swimming, he said.

For Michael Bradford, 45, and Liz Randolph, 44, of Queens, the news of the shark attack was not cause for much concern, though they said they were staying close to shore while swimming at Beach 59th Street.

“We noticed there was a drone earlier, and that afforded some reassurance,” Mr. Bradford said after emerging from the water, adding, “There’s a part of me that actually wants to see a shark, believe it or not.”

The kind of attack that Ms. Koltunyuk suffered is “the rarest of the rare,” Hans Walters, a field scientist with the Wildlife Conservation Society’s New York Aquarium, said.

Mr. Walters said the biting did not signify the start of a wave of shark attacks and was not a reason to abandon beach days. Rather, he said, the attack was a reminder to beachgoers to always be aware of their surroundings.

“I really think it’s up to us to realize that the ocean is not a bathtub or a swimming pool — it’s a wilderness area,” he said.

However, his team of researchers, as well as other scientists, is looking into an uptick in recent years in the number of reported shark sightings and encounters in New York waters, specifically on Long Island, he said.

At other New York City beaches on Saturday, any fear of sharks was not keeping people out of the water.

“We’re scared, but we’re going in,” said Sebastian Jimenez, 31, of Bedford-Stuyvesant, Brooklyn, who was swimming with friends at Beach 60th Street. “We’re keeping it in mind, but we’re still going in.”

At Coney Island, Stephanie Lazo, 30, said that her family already stayed close to the sand when swimming.

“I have a fear of the kids’ drowning more than the chances of a shark attack, which are really, really slim,” she said.

And at Beach 67th Street, about half a mile from where Monday’s attack occurred, surfers said they were used to sharing the water.

“I’ve been surfing here for 27 years,” said Clarance Tobias, 45, a surf instructor and co-owner of the surf shop Breakwater Surf Co. “We see sharks all the time. You run into them all the time.”

Shark bites are usually a case of “mistaken identity,” said Scott Curatolo-Wagemann, fisheries director with the Cornell Cooperative Extension in Suffolk County, N.Y., and an investigator for the Global Shark Attack File, an unofficial database of shark encounters. Sharks have always been in New York’s waters, said Mr. Curatolo-Wagemann — who was himself bitten by a shark in the Bahamas in 1994 — but increased monitoring means people are more aware of the animals’ presence.

To stay safe, beachgoers need to take some precautions, he said: Swim in groups, and avoid areas where there are a lot of bait fish and where birds are diving into the water.

On Saturday, it wasn’t a shark sighting that cleared the sand at Beach 59th Street. Shortly before 3 p.m., there was a clap of thunder, and the wind picked up.

People started packing up to leave, as clouds rolled in and the waves crested higher. It was raining.

Olivia Bensimon and Sadef Ali Kully contributed reporting.