Maritime boundary rejig to aid WA coffers

The West Australian government is salivating at the prospect of a revenue boon from the Browse gas field thanks to a redrawing of the nation's maritime boundaries.

But the rejig is some four years away from being finalised.

Now half-way through an eight-year project to undertake a complete inventory of all features that may contribute to Australia's nautical outer limits, Geoscience Australia has revealed the discovery of coral boulders and outcrops on North Scott Reef and Seringapatam Reef off the Kimberley coast.

They will prompt a redrawing of state and federal maritime boundaries, which could substantially increase WA's stake in the Browse gas field, boosting royalty revenue.

Mines Minister Bill Marmion said it was an exciting development and potentially a big windfall for the state, but the significance of the find was still being ascertained.

Geoscience Australia said it was expected the redetermination of boundaries in 2018 would be "final and permanent".

It said the coral boulders and outcrops sat several metres above the surrounding reef platform.

The boulders are generally less than five metres in width and pop about one metre out of the water when the tide is high.

The reef platforms on which the boulders sit are dry at low water.

"It is the broad extent of the exposed reef platform that generates maritime jurisdiction," Geoscience Australia said.