It appears with low tide and shifting sands - the skeletal remains of a shipwreck on Streedagh beach in Co Sligo. 

Known locally as the Butter Boat, various tales have been told of its origins but the true identity of the wreck has only just been confirmed thanks to detailed research led by the National Monuments Service. 

For at least twenty years some of the NMS underwater archaeologists have been investigating the famous Spanish Armada wrecks which lie off Streedagh and they were intrigued by the bones of the boat peeking out of the sand at low tide and the local folklore surrounding it.

Was it named the Butter Boat because of its shape or its business, could it possibly be from the Armada, was it a tourist boat as one record had it, or was it something else entirely? 

They began with a scientific analysis of the timber and dated the boat to some time after 1712.

Underwater archaeologist Karl Brady said this gave them a clue to take to their database of over a hundred wrecks off the Sligo coast in the 18th and 19th centuries.

Working with various historical resources including the National Folklore Collection (UCD) and newspaper accounts they were able to make a match with a wreck.

The remains of The Butter Boat at low tide

The Butter Boat is actually The Greyhound, a coastal trading boat out of Whitby in Yorkshire which sank in a storm in December 1770. 

With the identification of the wreck came a tragic story. The Greyhound had been caught in a storm off the coast of Mayo. 

Unable to seek safe harbour in Broadhaven Bay, it was driven to anchor in a perilous position beneath Erris Head and the crew abandoned ship.

However, in the panic there was a tragic oversight and a cabin boy was left on board. 

When the crew realised the boy was still on board, some of them, along with local volunteers and the crew of a passing ship, Mary, from Galway, set out to rescue him and managed to get back on board The Greyhound.

However, due to the severity of the storm, the vessel was ultimately forced ashore at Streedagh point where 20 of 21 people on board tried to get ashore but fell into a hole between rocks and were drowned.

The one survivor had stayed on the boat and when it eventually came onto the beach he made his way to a wakehouse and alerted local people who went to the scene, but all on board had been lost. 

250 years after the sinking of The Greyhound, those who perished were remembered in a small ceremony at what remains of the wooden boat.

Eddie O'Gorman of the Spanish Armada Ireland group was pleased that the mystery of the Butter Boat had been solved and said it was important to remember those who had died in their locality all those years ago.

The group has a small museum in nearby Grange where the Butter Boat is mentioned alongside the story of the Armada Ships which sank in the same area in 1588 but now Eddie says, the full story can be told. 

Fionnbarr Moore, Senior Archaeologist, National Monuments Service

For Michael MacDonagh, Chief Archaeologist with the National Monuments Service, the unearthing of the story of The Greyhound is a wonderful example of the power of archaeology to tell a story thanks to the bringing together of science, research and folklore.

Telling the human story is very important, he said, and gives people a whole new perspective on this well-known shipwreck. 

Mr MacDonagh said that further research will be done on the people who were on board The Greyhound and the National Monuments Service will be working in partnership with local people and the local authority to bring the story to visitors to Streedagh in the future.