A team of archaeologists has uncovered what is believed to be the oldest known shipwreck from Europe's Golden Age of Exploration. The wreck, found off the coast of Oman, was part of a fleet led by legendary Portuguese explorer Vasco da Gama during his second voyage to India.

Investigation of the wreck site revealed the ship was Esmerelda, one of two ships that sank during a storm off the coast of Oman in 1503.  

The wreck site was first discovered in 1998 and excavated between 2013 and 2015 in a joint effort led by the Oman Ministry of Heritage and Culture and the British shipwreck recovery company Bluewater Recoveries.

Among the many artifacts found at the wreck site was an incredibly rare silver coin called an Indio, of which only one other is known to exist today.  David Mearns, the director of Blue Water Recoveries, explained that the coins were forged in 1499 after da Gama's first voyage to India. This, he said, helps date the wreckage.

"The extreme rarity of the silver Indio, as only the second known specimen in the world, and the fact it was used specifically for Portuguese trade in India, is by itself a strong indicator of the ship's nationality," Mearns added.  

Although no large ship structures were found, researchers were able to recover more than 2,800 artifacts, including stone cannonballs engraved with what appear to be the initials of Vincente Sodré, who was da Gama's maternal uncle and the commander of the Esmeralda.

Mearns identified the wreck site about 28 miles from mainland Oman, off the coast of the remote Al Hallaniyah Island.  

"The bay where the site is located was almost a perfect geographical match for where the ship wrecked, according to the descriptions of the chroniclers," Mearns said.

Other exciting discoveries made at the wreck site include a metal disc bearing the Portuguese royal coat of arms and an image of an armillary sphere, and a bronze bell boasting the inscription "498," which suggests the ship was built in 1498.

"It is difficult to believe that the site can be anything but the wreck of either the São Pedro or Esmeralda," Mearns said.

However, excavations are ongoing and further research is required.

Their findings were recently published in the Journal of Nautical Archaeology.