Divers Recover 300-Year-Old Glass Onion Bottles From a Shipwreck Off the Coast of Florida

The fragile 18th-century containers, which likely held alcoholic beverages that were shared among passengers and crew members, survived for centuries at the bottom of the Atlantic Ocean

Bottles against a black backdrop
Layers of glass were flaking off the bottles due to a process known as "delamination." Conservators coated the artifacts with an acrylic resin to help preserve them. Florida Division of Historical Resources

In 2021 and 2022, divers recovered artifacts from a Spanish ship that sank off the Atlantic coast of Florida in the early 1700s.

Now, some of those long-lost items are finally revealing their secrets. Conservators in Florida spent seven months cleaning, drying and preserving two rare “onion bottles” that were likely made in England.

Archaeologists were thrilled to discover the intact bottles, as they more often recover only small fragments.

“These bottles are very fragile, and for them to first survive the destruction of the ship and then being submerged underwater for over 300 years where they were subject to tidal forces is incredible,” Mark Ard, a spokesperson for the Florida Department of State, tells McClatchy’s Mark Price.

Today, the glass bottles are empty. But three centuries ago, they were likely full of some sort of alcoholic beverage that was shared among the ship’s passengers and crew members. They were likely crafted by skilled glass-blowers.

“Onion bottles are free-blown using a pontile,” Ard tells Fox News Digital’s Andrea Margolis. “Each one is unique, so there is variation in size, shape and weight.”

They’re also quite delicate. By the time the onion bottles were found, they had become encrusted with sand, shells and aquatic organisms after being submerged underwater for so long.

Additionally, they had started to undergo a process known as “delamination.” This causes flakes of glass to start separating from the surface, which creates an iridescent sheen.

“Peeling back the layers to these onions was surely a challenge!” per a Facebook post from the Florida Division of Historical Resources.

Conservators started with a “meticulously” slow cleaning and drying process. Then, they coated the bottles with several layers of an acrylic resin material called Paraloid B-72. This helped prevent any more glass from flaking off and gave the bottles a shiny new look.

Florida officials have not revealed the name of the ship from which the onion bottles were recovered. However, they did share that the wreck is located near Indian River County, an area about 150 miles north of Miami.

The ship was part of a fleet of vessels sailing from Cuba to Spain in 1715. When the so-called “Plate Fleet” ran into a hurricane along Florida’s east coast, 11 ships were lost. The fleet’s name comes from the silver coins the ships were hauling, called plata. It’s also referred to as the 1715 Treasure Fleet.

Only those who have obtained a permit are allowed to explore the wrecks, which are located on state-owned lands underwater, report Treasure Coast Newspapers’ Gianna Montesano and Greta Cross. The state of Florida can claim up to 20 percent of artifacts discovered at the wreck sites, which are then placed in museums.

Examples of onion bottles are on display at institutions throughout Florida, including History Miami, the Pensacola Museum of History and the McLarty Treasure Museum. The two newly conserved bottles are now part of the state’s artifact loan program, which includes nearly 100,000 objects on loan to more than 100 researchers and institutions.

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