Shipwreck hunters will make a new expedition to the Abrolhos Islands in a bid to solve the 300-year-old mystery of the lost Dutch ship the Aagtekerke, which is thought to have gone down along the WA coast.
Hugh Edwards and his team believe the Aagtekerke struck Half Moon Reef in the archipelago off Geraldton when it disappeared en route to Indonesia in 1726.
Next month they hope to find some of the three tonnes of silver coins the ship was carrying between the Cape of Good Hope and Jakarta that could prove the wreck is in the Abrolhos Islands.
In light of the growing evidence gathered by Mr Edwards and his team, WA Museum maritime archaeologists are now also planning to survey the archipelago.
In 1968, Mr Edwards was among the finders of the Zeewijk, which sank on Half Moon Reef in 1727.
But the discovery of elephant tusks, which were not listed on the Zeewijk's inventory but were part of the Aagterkerke's cargo, has led experts to believe the reef could be home to both wrecks.
"We have looked all over the archipelago for the other ship but have never been able to find it," Mr Edwards said.
"So we have come to the conclusion there are two wrecks at that site."
Mr Edwards said they also found 44 guns at the Zeewijk wreck site, more than the usual number of 36 on such a ship. Nine anchors were also found when the Zeewijk would not usually have had more than six.
"The Aagtekerke loaded 214 elephant tusks as part of the cargo at the Cape of Good Hope," Mr Edwards said.
"The Zeewijk did not have elephant tusks. But among the difficulties is that both ships were built in the same shipyard by the same shipwrights.