Three men have died after their boat capsized off Sydney's southern coastline.
Emergency services were called to Henry Head Lane at La Perouse about 12.30pm on Sunday following reports a boat had capsized near the lighthouse.
Three men - who have not been formally identified - were retrieved from the water but couldn't be revived.
"Once we got the first two people on board, we were unaware there was a third person," Westpac Life Saver Helicopter crewman Clayton Allison told Nine News.
"Given that we had two critically ill people on board the aircraft, we made a decision to return to the base where we could commence resuscitation."
A second helicopter retrieved the third man.
Authorities continued to search nearby waters but it is not believed any other occupants were on board.
"It goes to show how quickly a situation can change - it is an absolutely disastrous way to end a weekend," NSW Ambulance duty operations manager Geoff Senior said.
"There are going to be grieving families after (the) tragedy and our hearts go out to them."
In a separate boating accident, a 40-year-old woman died on the Murray River in the state's south on Sunday afternoon.
A man and three children were rescued after the boat struck a submerged tree and capsized.
The woman's body was discovered about an hour later.
© AAP 2020