'It was horrible': Bondi to Bronte swimmers treated for hypothermia in chilly waters

One of Sydney’s biggest swimming events has turned into an ocean rescue as more than two dozen competitors were treated for hypothermia.

The race began on Sunday about 9.30am. The temperature was 15 degrees – seven below the average for December.

The organiser of the Bondi to Bronte event, Basil Scaffidi, said they decided to change the race route and keep competitors swimming near Bondi.

“We decreased it by about 10 to 15 per cent. It's normally about a 2.1 kilometre swim and we reduced it to 1.8,” he said.

But despite the change, 25 swimmers became overwhelmed with the cold and had to be treated at the beach for hypothermia. Three were taken to hospital.

Some had to be pulled from the surf. Others only felt the effects after crossing the swimming line.

Maddison Murray said she hit the sand and couldn’t walk.

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“I didn't have recollection of where I was or who I was or what I just did,” she said.

“It was horrible.”

One swimmer said he started to “get the shakes” after he got out of the water. Another said he could feel the cold “coming in a little bit” around his chest.

Surf Lifesavers NSW’s Chris Lorang said it was “very chilly” and the further out swimmers go, “the colder it gets”.