Tom Pembroke will attempt the 70 kilometre swim when the currents are at their coldest. 

Pembroke is using the swim to raise money for local Sara Lynch who was diagnosed with Acute Lymphoblastic Leukaemia at aged 10. 

“I want this swim to recognise the incredible spirit and bravery of Sara and her family,” he said.

“Since her diagnosis in 2015 she's had to undergo chemotherapy, and endured 16 operations, 13 lumbar punctures and six bone marrow tests. Sara has been lucky to have a loving, supportive family, but they have struggled with the financial, psychological and logistical challenges of her treatment in Sydney. This swim is for her and I hope to raise $30,000 to ease some of the pressures on the Lynch family and to raise awareness of the many other heroes that are personally dealing with cancer.”

To prepare for the chilly waters, Pembroke has been clocking up nearly 40 kilometres each week at Dumaresq Dam. He said while he expects the cold to affect him, he said there are other concerns on his mind. 

“There are likely to be schools of jellyfish, water temperatures as low as 13 degrees and this is the busiest shipping channel on the planet,” he said.

“The tankers all empty their waste tanks, so there's a lot of filth in the water, and the swell can make me very sick.”

To support Tom's swim go to www.gofundme.com/sara-lynch-our-hero?lang=en-A