The 1400-metre double crossing boasts a cash prize of $3500 split across male and female podium finishers.

Stockton Surf Life Saving Club president Callan Nickerson said he hoped ideal conditions on Australia Day would draw a record number of competitors and spectators to the event that has been running since 1995.

The annual swim is the surf club's largest fundraiser and is sponsored by the City of Newcastle and Port Waratah Coal Services.

"The swim means we can raise vital funds for our surf patrols and lifesaving operations at Stockton beach," Mr Nickerson said.

The prizemoney on offer makes the Newcastle Harbour Swim the richest open water swim in Australia.

Entrants must be 14 or older to participate in the 1400-metre double crossing, and 12 or older to swim the 700-metre lap.

Swimmers in the 700-metre event are allowed to use flippers and other swimming devices.

It is the only day of the year the harbour master allows swimmers to cross the world's largest coal port.

"We've had people in their eighties do the swim, it's a lot of fun, and there will be plenty of water safety on hand in IRBs, boards and skis to make sure everyone has a great day," Mr Nickerson said.

The race starts at 10am on the Stockton side for the 700m and at 11am at Queens Wharf on the Newcastle side for the 1400m.

For more information, or to enter, visit www.oceanswims.com.