Protesters in kayaks and canoes yesterday blocked the Newcastle shipping channel over the expansion of the coal export industry.

More than 100 climate change protesters formed a flotilla to stop coal ships from passing in and out of the harbour. They blocked the port for 4½ hours.

One protester was taken to John Hunter Hospital with minor injuries after her craft and a police power-ski collided.

The Greens NSW Senator Kerry Nettle was one of the protesters while hundreds lined the shore demonstrating with banners and placards.

Senator Nettle said: "If Labor and the Government were serious about stopping climate change they would have a plan for the transition from dirty coal to renewable energy, but they don't."

Water police escorted two coal ships through the blockade at 8.30am and 2.30pm.

Georgina Woods, from the Rising Tide Newcastle action group, said the protest - the third against the proposed third coal export terminal - was another success.

"It is clear the community is calling for change, and that our governments need to heed that call," she said.

Ms Woods said more peaceful direct action protests were planned for the coming weeks.

She said proposals to double Newcastle coal exports were approved by the NSW Government in April, with the full support of the Federal Government and Opposition.

"We cannot let this happen. We have a responsibility to force Governments to see sense," she said.

'Hundreds of community members have pledged to take peaceful direct-action to prevent the expansion of coal mining and exporting.

"That means more civil disobedience: against new mines, against the third coal terminal and against Governments while they continues to accelerate greenhouse gas emissions."

- with AAP