This is a battle on the beach.

Mayor Bill de Blasio and Police Commissioner Dermot Shea made waves Friday when they debated which beach was the best in the Big Apple – before Memorial Day weekend began.

The mayor, an old Brooklyn man, said he would always support Coney Island Beach.

“This is an oceanfront, this is a beautiful beach, let alone entertainment and everything,” Hizzoner said at the City Hall press conference.

Shea said she begged differently.

“I love Typhoon, I certainly love Brooklyn … but there is no comparison,” said the top police. “The number one beach is definitely Rockaway Beach.”

“We have a little bit of regional pride here,” Hizzoner answered. “So, I respect you as the proud son of Queens and I will continue to emphasize the superiority of Coney Island.”

But the two beaches – and the others in the city – will lose their charm this weekend because beach bums won’t be allowed into the water.

The Parks Department will take the lead in enforcing the rules, although the NYPD will intervene if necessary, the mayor said.

As many as 150 Park personnel will be available on the city’s beaches over the weekend, and hundreds of NYPD police will be present.

“You will see a number of police officers in uniform both on the beach and in the park,” Shea said. “But they will be there as servants. The last thing we want is at a stressful time for this city to use calls.”

During Thursday’s press conference, Brian Conroy, assistant chief of the NYPD Patrol in Borough of Brooklyn South, drew up guidelines which stated that surfing would be permitted on the beaches of the city but not swimming.

Neither De Blasio nor Shea mentioned the regulations on Friday.

Lifeguards are not ready yet, but social distance training begins this week, said City Park Commissioner Mitch Silver.

The entire process is expected to take “several weeks,” according to Silver.

“At that point, we will work with the mayor and other public health guidelines to determine when it is safe to return the coast guard,” he said. “The coast guard will be ready long before we can push deeper to reopen the beach.”

Group meetings, as well as volleyball and other sports, will not be allowed on the beach this weekend, said de Blasio.

“You can walk on the beach, you can walk on the beach,” Hizzoner said. “But do it in a way that is consistent with what we are talking about.”

Beach visitors should pay attention to social distance and wear face coverings.

“Whoever considers it unfair, the responsibility stops with me,” de Blasio said. “This is a decision I made as the elected leader of this city to protect us all.”

The Mayor called the Memorial Day weekend “a time to redouble our efforts, not losing our focus” – and that fewer restrictions will come in due time “if we play this correctly.”

“If we play it wrong, [we] “I will step down,” he said.

MTA on Thursday begs beach visitors to stay away from trains and buses during the Memorial Day weekend, and leave public transportation only for important workers.

For New Yorkers who don’t want to travel far to the beach, 13 more roads will be opened to walk across the city, to allow increased social distance, de Blasio said.

A total of 8.8 miles will be supported by the local area, another 1.8 by environmental organizations, and 2.7 miles will be bordered by parks.

With this new addition, 45 miles of roads will be open to pedestrians in the city.

“This now means we have more operational open roads … than anywhere else in the country because we have found a model that works and is very, very satisfying seeing how everyone works together,” de Blasio said. “We will continue to build it through this crisis.”

The aim, the mayor said, would expand to 100 miles of open roads before the end of the pandemic.