More than four centuries after English adventurer Sir Francis Drake went to his watery grave off Panama's coast, archaeologists believe they have found two of the last ships he commanded.

In emerald Caribbean waters where the privateer is said to lie buried in a lead coffin, explorers using deep sea oil technology found three large ship sections offering strong clues that they belonged to Drake's Elizabeth and Delight.

Famed for circumnavigating the globe and routing the Spanish Armada in 1588, Drake is also remembered as a slaver and pirate who acted with the blessing of Queen Elizabeth I.

More than 24 metres of well-conserved hull sections dating back to Drake's era show signs of having been run aground and burned to the water line, consistent with the tale of how his crew scuttled the vessels before returning to England.

James Sinclair, the lead marine archaeologist on the team that made the find, said the weight of evidence in support of the theory seemed "almost overwhelming".

"This may indeed be the two ships that Sir Francis Drake's crew scuttled at the end of his expedition down here," said Mr Sinclair, an eminent marine archaeologist who has led research on the Titanic and other historic wrecks.

In a cove near Drake's Point, an islet known as Drake's Island and near to where Drake was laid to rest in 1596, the wreckage shows vestiges of lead sheathing - a shipbuilding feature of that time - and remnants of period ceramics.

Mr Sinclair says more site excavation and wood tracing and dating will be needed to further corroborate the theory.

The greatest find - the remains of Drake, who was born in Devon around 1540 - has so far eluded what has likely been the most extensive, high-tech survey of the murky site.

"It's the new technology that's been created for the oil and gas industry that's making this happen," said Jay Usher, a remote technology expert involved in the project.

For a moment Mr Usher thought they had found Drake's casket.

"It was the right size, the right length, the right width," he said.

"People got excited. But when we dove down on it, it was basically a piece of concrete. It was gut-wrenching."

Drake's remains are just a hint of what could be found in waters that may have claimed two of Christopher Columbus's ships and vessels belonging to Henry Morgan, who sacked Panama City.

Drake, who tormented England's mighty rival, Spain, in the Caribbean for a quarter century, is said to have called Panama "the treasure house of the world."

Colonial Panama was the Spanish bridge between the Atlantic and Pacific, and the gateway for gold and silver plundered from the New World.

Harry Kelsey, author of the biography Sir Francis Drake: The Queen's Pirate, said though "absolutely fearless", Drake was probably not the sort of man who endeared himself to his peers.

"He was a slaver and so was the queen. I don't think he was really liked by a lot of the people who knew him and I'm sure he wasn't liked by people who served on his ships," he said.

Yet the legend of the sailor who set back the Spanish invasion of England by a year with a devastating attack on its fleet in Cadiz lives on in the hearts of many Englishmen.

"He was a commoner, he was one of us," said Mr Usher, a native of Liverpool, once a famous English slaving port. "(He was) a protector of the crown, a protector of the queen."

Reuters