She leaves on Sunday.

Karras and five team-mates will swim the channel in hopes of raising $25,000 for the Fred Hollows Foundation.

Chloe Jones from Warrnambool will team up with Karras, as will four girls from the Jersey Islands in the United Kingdom.

She first swam the channel when she was 12-years-old, and in a team of six the crossing took 12 hours.

"I wanted to encourage some of the younger people," Karras said.

"I just love swimming and had the thought to do it again."

In preparation Karras has been swimming laps of the bay in Warrnambool with water temperatures ranging from seven to 14 degrees.

"In the channel it is about 16 degrees so it will be like a bath but it is good toughening up," she said.

"Last time I did it, all of my team got seasick except me."

The crossing is notoriously tough with swimmers only allowed to wear bathers, goggles and a swimming cap to protect them from the elements.

"It is a stupid rule but we can't wear wetsuits or the crossing doesn't get recognised," Karras said.

"The only sharks that are there are basking sharks and they only eat krill, but there are a few jellyfish."

To the end of 2005, 817 people had completed 1185 verified crossings.

Swimming the channel has been a significant feat of endurance since Englishman Captain Matthew Webb first completed the swim in 1875.

"It is a big thing over there and well respected - I want to do it solo in two years," Karras said.

"Last time when we finished in Calais (France) everyone was onhand and offering us warm showers and stuff."