As protests against a plan to drill for oil in the Great Australian Bight take place around the nation, an event on Western Australia's south coast is particularly poignant for locals.

Key points: Protests against oil drilling in the Great Australian Bight were held in more than 50 towns across the country on Saturday

Protests against oil drilling in the Great Australian Bight were held in more than 50 towns across the country on Saturday In Esperance, on WA's south coast, memories of the Sanko Harvest oil spill were triggered

In Esperance, on WA's south coast, memories of the Sanko Harvest oil spill were triggered In 1991, the Sanko Harvest ship ran aground and spilt 700 tonnes of oil around 35 kilometres from Esperance

According to the Maritime Safety Authority, Esperance is one of the only towns in the country to have experienced a major oil spill.

Cheryl Bradley, who addressed a 560-strong crowd on Saturday, remembered all too well risking tuberculosis as she worked to scrub oil from seal pups after the Sanko Harvest ran aground in 1991.

"It was a massive task," Ms Bradley told the demonstrators.

"We loaded up the SES [State Emergency Service] vessel with supplies and steamed out."

After Ms Bradley spoke, protesters paddled out into the Southern Ocean to register their opposition to Norwegian company Equinor's plan to drill for oil.

A horrible first

It was 3:20am on February 14, 1991 when the Japanese cargo ship, Sanko Harvest, ran aground 35 kilometres from Esperance, near a beach known for having the whitest sand in Australia.

The front page of the local paper after the Sanko Harvest ran aground in 1991. ( Supplied )

Although it took a few days for the impact of the crash to sink in, Ms Bradley said the whole town was soon buzzing with the news.

A relief teacher with flexible working hours, Ms Bradley was asked to help clean up the New Zealand fur seal colony at nearby Hood Island.

After hauling all kinds of supplies to their island base — star pickets, wire, tools, 20-litre containers of detergent, scrubbing brushes, hazard overalls, rubber gloves, tents, and food for starving seal pups — they then had to work out how to clean a seal.

"Seriously, it was the first time anything like this had ever been attempted," Ms Bradley said.

She described building a pen and herding the seals into it, before "catching the pups, one at a time, and wrestling them to the ground".

"They were very strong and very slippery, obviously," Ms Bradley said.

Cheryl Bradley (in black swimsuit) helps clean up after the Sanko Harvest oil spill in 1991. ( Supplied )

'One of the most tragic things I've ever seen'

The volunteers worked in teams of three.

One person would hold the animal's head to stop the others getting bitten, which carried the risk of them getting tetanus, another would hold the seal's back end, and a third person would apply detergent.

This third person would rake their fingers through the pup's fur to try and pull the oil out, which Ms Bradley said was "not like cooking oil".

"It was one of the most tragic things I've ever seen, the sight of these seal pups, which are adorable creatures," she said.

"They're just covered in this black oily substance — a tarry substance.

"And they were rubbing their eyes on their oil-affected shoulders, because their eyes were almost completely covered in oil, and every time they rubbed their shoulders they were just reinfecting their eyes.

"This was a thick, black, tarry sludge which had drenched the pups almost down to the skin."

Ms Bradley spent three days on the island, tending to about 40 seal pups.

Meanwhile a massive effort was underway at the local beaches where volunteers shovelled oil off the pristine white sand.

After a few days Ms Bradley said the oil slick was washed along a little further down the coast to another seal colony, this one with about 160 pups.

Thanks to the efforts of the volunteers it is believed about 80 per cent of the colony survived.

More than 500 people in Esperance protested against oil drilling in the Great Australian Bight. ( Supplied: Hayden Smith )

A question of risk

Equinor, which plans to start with one exploration well in the Bight next summer, has stated on its website that "any oil spill is unacceptable to us".

But the company has also said a blowout would take at least 15 days to cap.

This is because the equipment needed to stop the spill — a capping stack — would need to be airlifted from Singapore, reassembled, and taken out to the well by a "large crane vessel".

In that time, oil could have travelled across — and reportedly even beyond — the Great Australian Bight.

Further concerns have been raised about how a response program would be coordinated, especially one forced to contend with the notoriously rough waters in the Southern Ocean, and the plan to use dispersants if an oil spill occurred.

But before Equinor does anything, it needs to get approval from Australia's National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA).

On November 8, NOPSEMA asked Equinor to modify and resubmit its environmental plan as it had done on June 27.

It has 21 days to respond to this.

But some think that because there will always be an element of environmental risk, NOPSEMA should ban Equinor from drilling entirely.

A newspaper article describes the plight of the seal pups during the Sanko Harvest oil spill. ( Supplied )

Councils in opposition

More than 18 local governments have taken a stand against the planned drilling, including the Esperance Shire Council.

Shire president Ian Mickel recently joined the council when the Sanko Harvest ran aground in 1991, and said he remembered the "absolute disaster" it was for tourism.

"I think [denying the planned drill] is the only way to go," he said.

Ms Bradley echoed the sentiment.

"[I think of] the risk that the captain of the Sanko Harvest took by taking a shortcut through the inner archipelago," she said.

"He shouldn't have been there in the first place.

"It doesn't seem like it was an appropriate risk for him to take from an environmental point of view."