According to the the Bureau of Meteorology, hazardous surf is forecast across the Sydney, Macquarie, Hunter, Illawarra, Batemans and Eden coasts.

The bureau said the fronts will produce surf and swell conditions in the afternoon and evening, and will be hazardous for coastal activities such as rock fishing, boating and swimming.

Boaters are reminded to take extra care and be aware of hypothermia during winter months, they said.

"Skippers and owners of small crafts should be on high alert and check the conditions before considering crossing a coastal bar or heading offshore," NSW Roads and Maritime Services said on Tuesday.

"Rock fishers should also check weather forecasts before heading out, avoid fishing near dangerous surf and wear a lifejacket.

"Every skipper is responsible for the safety of their vessel and all on board.

"Boaters should remember to log on with their local Marine Rescue radio base, via VHF Radio or the Marine Rescue APP, and consider their safety management plan."

For more information, visit www.rms.nsw.gov.au/maritime and to check the forecast visit http://www.bom.gov.au/nsw/.