Seven Mile Beach stretches from Gerroa down to Shoalhaven Heads and Comerong Island - with the southern end badly affected by erosion.

The beach has virtually been swallowed up to back to the sand dune, leaving a dangerous four metre drop to access the water.

Shoalhaven Heads Surf Club president Karl Poulton has urged beachgoers to take care while trying to access and use the beach.

"It's very dangerous," Mr Poulton said.

"Really there is no beach left at all. Large swells have just stripped the beach away and we are virtually back to the dune.

"Accessing the beach, or what is left of it, is extremely dangerous.

"There is a three to four metre drop off just to get to the water."

He urged beachgoers to stay safe.

"The drop off is right out the front of the surf club building and extends 500 metres to both the north and south," he said.

"Beach access is extremely restricted.

"People virtually have to jump or drop three to four metres down just to get to the water."

He said beach patrols in the area would also be restricted due to the massive erosion.

"The surf club and professional surf lifesavers will continue to patrol the area seven days a week and will continue to do so until the end of the holidays, but how we do things will be vastly different to normal," he said.

"We will be particularly restricted when it comes to IRB (inflatable rescue boat) rescues - board and tube rescues will be fine but getting access onto the beach with the IRB will certainly be a challenge.

"We will probably be able to get it onto the beach - getting it off would be another matter."

He said it is anticipated patrols will have to be conducted from on top of the sand dunes rather than traditionally from the beach.

"We'll have to, simply because there is no beach."

He has encouraged beachgoers to try other locations to take their dip, such as to the north at Gerroa.

And it couldn't come at a worse time with the population of Shoalhaven Heads expected to triple over the next six weeks as we hit peak tourist season and thousands of people set to take their Christmas break in the seaside village.

"I'd say the village will be packed this Christmas," Mr Poulton said.

"It always is at Christmas time, but this year more than ever with COVID-19 restricting where people can go and virtually stopping overseas travel, more and more people are looking to holiday within the country.

"I'd say all the local caravan parks would already be at 100 per cent capacity.

"It's going to be massive - and also a massive headache for surf lifesavers as we try to patrol the beach and ensure everyone's safety on what is now an extremely dangerous and unpredictable coastline."

M Poulton said the club had contacted and been in discussions with Shoalhaven City Council and it was hoped "machinery can be made available to at least cut a safe access track onto the beach".

"It is a real safety concern," he said.

"You can't just expect people to drop down metres to get to the beach.

"And there is the risk of further sand slips, so if you are on the beach please don't sit near or especially under the edge of the eroded dunes.

"And if you are out walking the dog please don't go near the edges of the dune - we don't know how unstable they really are.

"There is always the risk of further collapse.

"We have reached out to council and we are hopeful they will be able to do something by early next week.

"They've helped us out in the past when we've had similar issues [the last was about six years ago] and hope they can again this year."

Christmas also traditionally means king tides and big seas in the area, with Mr Poulton fearful the damage could become even worse.

"We also get bigger tides and seas around Christmas/New Year and that's a big worry and will put even more pressure on the already stressed sandbase," he said.

"I suppose our clubhouse, which has just undergone major renovations and upgrades, could possibly end up like the one up at Collaroy, a little building sitting up on an island of rocks and everything else gone."

Mr Poulton who has been associated with the club since the 1980s has never seen the erosion this bad.

"We've had issues with beach erosion previously over the years but I've never seen it anything like this."

The extent of the erosion has led to comparisons back to 1976 when a similar massive erosion event occurred which also potentially undermined the surf club building.

That led to Shoalhaven City Council being forced to install massive amounts of large rocks in front of the clubhouse just to ensure its retention.

"I'd say we are nearly back to those rocks again," Mr Poulton said.

"It's massive."

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