Climate 'flotilla' launched near biggest coal port

Hundreds of climate activists have taken to the water near the world's biggest coal port with police trying to keep them away from an approaching cargo ship.

The multi-day "protestival" near the Port of Newcastle ramped up on Friday morning with participants attempting to occupy parts of the harbour and the foreshore with a flotilla.

More than 300 people entered the water in kayaks and began paddling out just after 11am, as part of a planned blockade.

Police launched a tug boat and put several buoys in place in a bid to contain the protesters to a small area.

A number of bulk carrier ships are due to berth on Friday, potentially endangering those in the water on lightweight craft.

Police have repeatedly flagged concerns over the safety of the event, citing a similar action in 2023 that resulted in the arrest of nine people who refused to exit the water at an agreed time.

Friday's event follows a successful last-minute legal challenge by organisers Rising Tide to overturn a government-ordered "marine exclusion zone" that would have prevented the protesters from entering the water.

As a result, the group said protesters could peacefully enter the water off Horseshoe Beach, near the mouth of the harbour, to conduct a flotilla without impeding the nearby shipping channel.

NSW Police Commissioner Karen Webb said the protest was still unlawful, a reference to an early court decision to deny organisers a permit.

"It is still against the law to disrupt a shipping line," she said on Friday morning.

"We're disappointed with the decision yesterday to lift the exclusion zone, but we're very prepared."

Transport for NSW issued the exclusion order a week earlier, including a maximum $1100 fine for anyone entering the water and $3300 fine for anyone in the vicinity who failed to comply with directions.

Rising Tide lawyer Felicity Graham successfully argued in the NSW Supreme Court the purpose of such zones was to protect public safety during "special events" on waterways, not to prevent them from happening.

During the hearing, protest organiser Alexa Stuart agreed Rising Tide promoted civil disobedience and said some of those at the event might break the law to draw more publicity to the cause.

"I would say it is likely," she said.

The event near the Port of Newcastle also includes live music and other activities to amplify a call to end the expansion of fossil fuel use.

Hundreds of children joined the action and rallied outside Customs House for a School Strike for Climate before joining the harbourside festival on Friday.

Frankie Kelly, a 12-year-old primary school student, has been participating in the weekend events.

"It is scary knowing that I am growing up into a world that is severely affected by climate change, especially when the government continues to approve new coal and gas projects," she said in a statement.

"But I feel a little bit better knowing there are people at the strike who will join us in fighting for climate justice."

Former federal environment minister and Midnight Oil frontman Peter Garrett will be part of the live music line-up.

Rising Tide is calling for an end to new coal and gas approvals, and the imposition of a 78 per cent tax on coal and gas exports to help fund the energy transition.