The trial, which is also occurring at Shelly Beach, will involve lifeguards patrolling the beach seven days a week, from 9am to 4pm, until the end of September.

The trial follows a council vote in March to do more to make Wyong Shire's two most popular beaches safer during winter.

"I know it's been cold of late, but you still get the local die-hards and groups of holiday-makers braving the conditions to swim at our beaches," Wyong Shire mayor Cr Bob Graham said this week.

"Quite often, the conditions in winter are more treacherous and if we can have our lifeguards available seven days a week and they end up saving just one life, then this trial will be well worth it, and something for council to seriously consider keeping in future."

Head counts at the two beaches would be an important part of the trial, council's manager of customer and community services, Danielle Dickson, said.

"We're looking at capturing how many swimmers are swimming at the two beaches at hourly intervals, and the lifeguards will gather that data electronically through hand-held devices," Ms Dickson said.

The patrols started on July 1 and will continue through until the start of the regular lifeguard season, council's manager of open space and recreation operations, Luke Sulkowski, said.

"At the start of the regular season, the volunteer lifesavers will be back patrolling beaches on the weekends and our council lifeguards will revert to weekday patrols between 8.30am and 5pm."

The trial is expected to cost $170,000.