New laser scanning analysis has identified an artefact recovered in an expedition led by Midhurst-based ship wreck hunter David Mearns, as the oldest navigation instrument ever discovered.
In March 2016 David, director of Blue Water Recoveries, uncovered the 500-year-old wreck site of the Portuguese Armada ship Esmeralda, captained by an uncle of the legendary explorer Vasco da Gama, Vicente Sodre. He had led a three-year archaeological project in collaboration with Oman’s Ministry of Heritage and Culture.
The ship sank off the coast of Oman in 1503, only five years after Da Gama discovered the first sea route from Europe to India, making it the oldest pre-colonial shipwreck ever discovered.
Very little of the ship remained but some 2,800 artefacts were uncovered.
The most exciting, said David at the time, was a metal disc bearing the Portuguese coast of arms and an image of a sphere which was the personal emblem of the then King of Portugal.
Now laser scanning has confirmed it is oldest mariner’s astrolabe ever discovered – only 104 examples are known to exist.
The astrolabe is a rare navigation instrument used by the Portuguese mariners.
“It is entirely possible this is the type of astrolabe used by Vasco da Gama during his famous voyage that discovered the sea route to India in 1498,” said David.
“Without the laser scanning work performed by engineers at the University of Warwick, we would never have known the scale marks, which were invisible to the naked eye, existed. Their analysis proved beyond doubt the disc was a mariner’s astrolabe. This has allowed us to confidently place it in its correct chronological position and propose it to be an important transitional instrument.”
It will be listed in the Guinness Book of World Records as the oldest mariner’s astrolabe from as early as 1496.