Multi-agency rescue operation for three boaters near Wedding Cake Rock

It's understood the men - believed to be aged in their 50s - were on a fishing expedition at the time of the incident near Wedding Cake Rock, around 9.40am.

"We believe the men had been fishing when a freak wave caused their boat to overturn," a NSW Ambulance spokesperson said.

"They'd been in the water for around an hour before they were spotted by a bushwalker who called for help."

A multi-agency response was then enacted to rescue the trio.

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One man was winched to safety by the NSW Police PolAir helicopter and the other two winched by the Westpac Rescue helicopter.

A NSW Police spokesman said all men were taken back to land at nearby Wattamolla Beach where they were treated for mild hypothermia and suspected water inhalation by NSW Ambulance paramedics.

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They were then transported to Sutherland Hospital in a stable condition. The boat was towed back to shore by Marine Area Command and Maritime Services.

"Thankfully, they were wearing life jackets which may have prevented a much more serious situation," the police spokesman said. "This is a timely reminder to anyone heading out on the water to be prepared and ensure you have the necessary safety equipment on board."

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