Surfers, swimmers and sunbathers were outnumbered by police as people heeded police advice to stay away.
Up to 2,000 police, including riot and dog squads backed by helicopters and boats, were deployed over the weekend to patrol troubled beaches in the city and to the north and south.
The popular Cronulla beach in south Sydney, where racial violence first erupted last Sunday, was comparatively deserted as police staged random vehicle searches on approach roads.
A special task force set up to crack down on the violence made 19 arrests overnight on Friday, but most were for drunk driving, traffic and drug offences, police said.
Dozens of people were injured and arrested in riots after white mobs set out to "reclaim the beach" from groups of Australians of Middle Eastern descent, mainly ethnic Lebanese, at Cronulla last Sunday, sparking days of revenge attacks.
The New South Wales state parliament was recalled from its summer recess to pass legislation giving police extra powers to combat unrest, and police warned intelligence indicated gangs would target the beaches again this weekend.
"I would urge people who do not live in these areas to stay away unless they have a good reason to be there," police chief Ken Moroney said.
It was a surprising call in a country with a strong beach culture, but early indications were that it was being taken seriously.
The mayor of Sutherland Shire, which includes Cronulla, had called on beachgoers to defy requests not to visit the beach, saying local businesses had been hard hit as people stayed away over the past week.
"I urge honest law-abiding people who want to spend a non-violent day of fun in the sun to make their way to Cronulla and help support those innocent business operators," he said.
However, media have reported throughout the week on email, mobile phone and website messages calling for more "protests".
Meanwhile, the government announced a new program to promote respect and understanding between ethnic groups, including encouraging non-Anglo Australians to become lifesavers.
"We want to have a program which basically educates everybody on how to behave on the beach," said Minister for Multicultural Affairs John Cobb.
Some residents of Cronulla had complained that groups of ethnic-Lebanese from poorer inner-city suburbs descend on the beach at weekends and disrupt the easygoing atmosphere with aggressive behaviour.