Recent rough seas sparked by an undersea volcanic eruption near Tonga have uncovered rarely seen shipwrecks on the NSW Mid North Coast.
Maritime archaeologist Brad Duncan said about a metre of sand movement has led to further exposure of 50-year-old ferry wrecks, the Sydney Queen, Lurgurena and Koondooloo, at South West Rocks.
Dr Duncan said the turbulent seas have helped efforts to document the vessels on the beach.
"It gives us a better indication of where the vessels are and what's actually left on these things," Dr Duncan said.
Dr Duncan said the three decommissioned ferries were destined for the Philippines for repurposing or scrapping in January 1972. But the towline between the ferries and the towing tug Polaris was severed.
The Polaris managed to get to Trial Bay where the ferries were moored, but a strong wind a day or so later swept the vessels ashore onto the beach where they have remained ever since.
The recent rough seas prompted maritime enthusiast Corrinne Boon to head down to Trial Bay Front Beach to see if the wild weather had exposed any of the vessels.
Ms Boon stumbled across what is thought to be two engine steering sections of the Sydney Queen, also known as the Kalang.
She noted it's rare for beachgoers to see the historical artefacts of the wreck.
"As a longtime, many-decades resident of South West Rocks, I had not seen those in many years."
The conditions have inspired Ms Boon plan a visit to Crescent Head and along the coast to see if she can find other shipwrecks.
"I'm even looking for tiny fragments of timber or anything that might just look a little bit out of the ordinary or a little bit older than anything else," she said.
Predicting when shipwrecks emerge
Ms Boon and other shipwreck enthusiasts between the Tweed border and Eden work closely with Dr Duncan and Heritage NSW via the Department of Premier and Cabinet to document and photograph wrecks along the coast.
Part of their work in recent years has been to develop a model that aims to better anticipate when shipwrecks will be visible along the NSW coastline.
The team have found that the tops of a spring tide and big swells offshore, often associated with a low pressure system along the east coast, are ideal conditions that expose shipwreck sites.
"It means that now we've got a basic sort of predictive model which we're trying to finalise," Dr Duncan said.
He said the model will be useful in helping to locate new wrecks.
"So, when we know these conditions are coming up we can actually put the word out to our wreck spotters networks and say, 'Hey there's been a big storm coming through here, it's the spring tides, can you just check out these sites in your area'," Dr Duncan added.
He said the model would also help continue documenting well preserved vessels like Buster in Woolgoolga, which is one of the best-preserved wrecks in the country.
The Canadian-built 39-metre vessel has been a fixture on the main beach for tourists and locals since it washed ashore in 1893.
Overall, Dr Duncan hopes the project will help preserve maritime history in NSW.
