Botany Bay tragedy: Boatie Stuart Collings killed and brother-in-law Darren Curmi injured after their craft was struck by a whale and flipped

Harrowing new details have emerged of how a fisherman clung desperately to his dying brother-in-law for 45 minutes after a huge whale landed on top of their boat and knocked them into the water.

Water police rushed to the scene at Cape Banks in La Perouse, south of Sydney’s CBD, about 6am on Saturday after reports that two men were in the water at Botany Bay.

Stuart Collings, 61, and his brother-in-law Darren Curmi, 53, were thrown into the water after their boat was capsized by the pounding whale.

Mr Collings was knocked unconscious during the impact as Mr Curmi kept his brother-in-law afloat for 45 minutes as he desperately called for help.

Footage has emerged of the stricken unmanned vessel circling the water as water police and lifeguards try to gain control of the boat.

“The boat is just sailing in chaos, there is no one on it,” a witness explains in the video.

“Hopefully it doesn’t end up on the rocks.”

Stuart’s brother-in-law Darren Curmi was rescued and is now recovering in hospital

Mr Collings was pulled from the water but sadly died at the scene despite desperate attempts to revive him.

Mr Curmi, 53, who was transporting the boat, was rescued and taken to St George Hospital in a stable condition.

It is understood that the brothers-in-law were only half an hour into their fishing trip when disaster struck.

Shocked witnesses, including on the water just outside the heads of Botany Bay, said they heard a ‘big bang’ before the 4.8 meter boat overturned.

“Something big came out of the water, it was huge,” one person told The Daily Telegraph.

“It was still dark, but you saw this big black shape jumping out of the water.”

Water Police Acting Chief Inspector Siobhan Munro said the whale breached near or on the ‘running around’ boat, causing it to capsize.

“Right now there are a lot of whales and there are many examples of whales breaching next to boats… but this is a tragic accident,” she said.

NSW Police Minister Yasmin Catley offered his condolences to the deceased man’s family at a press conference on Saturday morning.

Images have emerged of the stricken ship sailing around the area after the bizarre incident

“It’s very early stages and there’s very little information that we know at this point,” she said.

‘(We) were told early on that a whale was involved, who would have thought this would happen?

‘It is terribly tragic and we sympathize with those family and friends.

“This morning two boys got up to go out and enjoy fishing, something I and most people in NSW enjoy doing, and found themselves in tragic circumstances.”

“I believe the skipper stayed as close to the deceased as possible and did everything he could to keep him afloat until the police arrived.”

The Foreshore Road Boat Ramp at Botany and surrounding roads were closed for much of the day as police launched an investigation.

Forensic officers spent the day assessing the fishing vessel for damage.

Police are still trying to figure out what happened. The incident is being treated as a freak accident at this stage.

Officers pulled two men from the water in Botany Bay, south-east Sydney, early Saturday morning (photo, emergency services on scene)

The second man was pulled from the water and taken to hospital by NSW Ambulance paramedics in a stable condition (photo, emergency services on scene)

Water police were called to the scene around 6am and officers recovered the deceased man unconscious from the water (photo, emergency services near the Foreshore Road Boat Ramp)

NSW Maritime director Mark Hutchings said an “incredible” number of whales are migrating along the east coast this year.

“If you’re on the water, you should be 100 meters away from an adult whale, and 300 meters away if that whale has a calf,” he said.

“The whales are not there to harm anyone, but those interactions can happen.”

One man died and another was hospitalized after their boat struck a whale and sailed off the coast of Sydney (photo, water police and paramedics on scene)