A father and son who were volunteer lifesavers from Port Campbell, in western Victoria, have drowned after being thrown into rough surf while trying to save an international tourist.

Key points: The tourist was wading near the mouth of a local river when he got into difficulty

The tourist was wading near the mouth of a local river when he got into difficulty Three people in the rescue boat were dumped into the water in rough conditions

Three people in the rescue boat were dumped into the water in rough conditions Two people, including the swimmer and another rescuer, were winched to safety

Ross Powell, 71, and his son Andrew, 32, died during the rescue of a 30-year-old man who police said was wading at the mouth of the Sherbrook River when he got into difficulty on Sunday morning.

Police said the six-metre rigid hull rescue boat was swamped in heavy surf conditions throwing three men into the water.

An emergency helicopter winched two men to safety — the man in the water and one of the rescuers, who was seriously injured.

The man who got into trouble was taken to hospital in a stable condition.

Police said there were signs warning tourist about the dangers of swimming at the Sherbrook River. ( ABC News: Sian Johnson )

The other man was airlifted to the Alfred Hospital where he is in a serious but stable condition.

In an emotional press conference Surf Lifesaving Victoria president Paul James called the pair heroes.

"It's just terrible, it's heartbreaking," he said.

"I understand the boat was operating in a two-metre swell, so a very high swell, and we know that it is very treacherous down there and not the place to be swimming.

"These brave people, these heroes, have gone out to try and help."

Surf Lifesaving officials said the pair were wearing their full personal protection gear when they went to rescue the swimmer. ( Facebook: Craig Lands Holsteins )

Mr James said the "highly experienced" volunteers were long-term members of the Port Campbell Surf Lifesaving club.

"The loss of these two lives is a tragedy and I know I speak on behalf of all Victorian agencies when I say our thoughts are with the family, the friends and community of Port Campbell," acting Emergency Management Commissioner Stephanie Rotarangi said.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 1 minute 2 seconds 1 m 2 s Two lifesavers die after rescue boat capsizes in Victoria

Victoria Police are investigating how the deaths occurred and will prepare a report for the coroner.

"Clearly it's a very tight-knit community, Port Campbell, and unfortunately it's a tragic set of circumstances," Senior Sergeant Brett Jackson said.

"I'm sure it's something that's really going to hit the community hard and unfortunately, it's just an event that should never have occurred."

Senior Sergeant Jackson said there were signs warning of rough surf and strong rips where the man went swimming.

Rescuers 'very brave'

Ian McCauley watched the rescue unfold as one of the men was winched from the water. ( Twitter: @ianmccauley )

Ian and Lisette McCauley were on holiday at Port Campbell when they watched as one of the men was winched to safety by an Ambulance Victoria helicopter.

"We watched … the chap being lowered down into the water while the helicopter hovered over the water and near the cliffs which is a professional bit of flying by the helicopter pilot," Mr McCauley told the ABC.

"Then the rescuer dropped into the water again, in turbulent conditions and very close to the cliff, where there was quite heavy swell breaking.

"He swam to the person and then the two were lifted into the helicopter."

Mr McCauley praised the professionalism of the rescuers.

"Certainly the person who was in the water rescuing the person was very, very brave," he said.

"We hope [it] shows the professionalism of the pilot at Ambulance Victoria and the bravery of the person who was lowered into the water, for probably the second time to grab someone out of there."