The reason - it's the Greater Australian Bight Alliance's national 'Fight for the Bight' day of action.

The day will see more than 200 community groups around the country, including the Culburra Beach Boardriders Club take part in one of the biggest environmental protests Australia has seen - paddling out against Norwegian oil-giant Equinor's plans to drill for oil in the Great Australian Bight.

The Culburra Beach leg of the surf protest will run from 9.30-10.30am at Ocean Street - which Boardriders vice-president Ty Watson hopes will be well supported by the Shoalhaven community.

"We'd love a big turn out on Saturday, to get as much attention as we can from Equinor as we can," Watson said.

"It's important we show them how many people will be affected by them possibly drilling into and ruining the Bight and surrounding areas.

"Our surf and coastline are what so many Australians, like myself, live for and if they are allowed to drill to ruin it for future generations.

"In terms of the Boardriders, we wouldn't be able to exist if they're allowed to drill, as it will put so much pollution into the ocean and destroy the delicate ecosystem as we know it."

On November 11, Equinor's plan to drill a well for oil 370km off the coast of South Australia, in the Great Australian Bight, was rejected for a second time, giving the oil-giant now 21 days from then to resubmit its environment plan to the government regulator - as they had hoped to start in late 2020.

Research by the Australian Institute supports Watson's stance, saying Australians are being asked to shoulder all of the economic and environmental risks of the project, while a foreign government is likely to enjoy much of the financial gain.

The study, authored by Rod Campbell and Tony Shields, states the Norwegian government stands to gain $400m more from drilling in the Great Australian Bight than the South Australian and federal governments combined.

It goes on to say two-thirds ownership of Equinor, the Norwegian government, stands to make $8.1bn from oil and gas exploration in the Bight - which compares with the equivalent of $7.4bn of revenue, for the federal government from company tax and petroleum resource rent tax and $300m in payroll tax for the South Australian government, over a 40-year period.

Gerroa's Sally Fitzgibbons has thrown her support behind the cause, as has other high profile surfers Mick Fanning, Stephanie Gilmore and Jack Freestone.

Other sites on the South Coast that will participate in the 'Fight for the Bight' day of action are Kiama and Mollymook.