As an epic storm lashed NSW last night, the families of Ross Napoleoni and Luke Des-Baux were praying for extraordinary luck.

Ross and Luke's boat had been spotted adrift nearly three kilometres off Port Kembla yesterday evening - and there was no sign of the two friends.

As the storm intensified and night fell, the search for them had to be called off.

But after a long night, Ross's stepmother, Michelle Napoleoni, said today the family had “won the lottery”.

The two men, who had been snorkelling off Toothbrush Island, had swum to shore after losing their boat and taken shelter from the storm in a cave.

They were spotted by a NSW Police helicopter at 8am and winched to safety.

They were hungry and covered in mosquito bites but were allowed to go home after a medical check.

Mrs Napoleoni said her stepson had used his snorkelling goggles to catch rainwater.

“They are pretty sensible guys,” she said.

“They had all the right gear on the boat - flairs, lifejackets - but the boat just drifted away from them.”

She said they had seen rescue boats searching a nearby island yesterday and tried to catch their attention.

“They were yelling and screaming but with the noise of the rescue boats they couldn't hear them.”

The rescue mission resumed at 7am this morning with the SES and rescue squad.

Lake Illawarra Police Duty Officer, Kevin Bale, said the helicopter hadn't been in the area long when they were spotted.

“They were still in their wetsuits when they were found with flippers, goggles and snorkels,” he said.

Mrs Napoleoni said they had headed home to rest but had first dropped in to see worried family members and even delivered them some fresh fish.

“The fish were still on ice in the boat [this morning] and they bought them back for us.”