Archaeologists Confirm Identity of 18th-Century Shipwrecks in Costa Rica

Archaeologists have confirmed the identity of two 18th-century shipwrecks in Costa Rica that for years were thought to be pirate ships. It has now been confirmed that the wrecks located in shallow waters off Cahuita National Park are those of Danish slave ships Fridericus Quartus and Christianus Quintus, which were shipwrecked off the coast of Central America in 1710.

The National Museum of Denmark is announcing that after analyzing samples taken from the shipwrecks, archaeologists have finally managed to resolve their mystery, bringing to an end years of speculation that they were pirate ships.

Historical Background

Records show that in 1708, the two ships sailed from Copenhagen via West Africa towards Saint Thomas in the West Indies. Over several months of sailing along the coast of West Africa, the holds of the ships were filled with hundreds of slaves and made ready for the long voyage across the Atlantic.

In the spring of 1710, the two ships were in the Caribbean Sea. During the voyage across the Atlantic, however, they had gone off course, sailing nearly 2,000 kilometers further west than their intended destination, the Caribbean island colony of Saint Thomas in the Danish West Indies.

Sailing off course resulted in food and water rations running low, and a mutiny broke out among the crews of the two ships. The ensuing melee resulted in Fridericus Quartus being set on fire. Christianus Quintus had its anchor cable cut so the ship drifted towards the coast, where it was crushed in the waves in shallow water and also sank.

Confirmation of Identity

The two wrecks were first discovered in the 1970s, but it was not until 2015 when U.S archaeologists discovered yellow bricks in one of the wrecks that renewed interest in the history of the ships. In 2023, archaeologists from the National Museum of Denmark and the Viking Ship Museum carried out a diving mission to the two ships’ resting place and took samples of wood and bricks that were part of the cargo.

Detailed analysis of the samples has returned results that are consistent with Danish medieval history and accounts of the two ships. Analysis of the wood showed the timbers originated in the western part of the Baltic Sea, with the tree having been cut down sometime during the years 1690-1695. The wood was charred and sooty, confirming historical accounts about one of the ships being set ablaze.

The bricks bore remarkable similarities to those manufactured in Flensburg for use in Denmark and the Danish colonies in the 18th and 19th century. Analyses of the clay showed it came from parts of Denmark that were home to a sizable brick-producing industry. The clay pipes were identified as ordinary, Dutch-produced pipes that were also used onboard Danish ships.

Conclusion

“The analyses are very convincing and we no longer have any doubts that these are the wrecks of the two Danish slave ships. The bricks are Danish and the same goes for the timbers, which are additionally charred and sooty from a fire. This fits perfectly with the historical accounts stating that one of the ships burnt,” said David Gregory, National Museum marine archaeologist.

The project that led to the identification of the two shipwrecks is part of a new mission by the National Museum to excavate several Danish shipwrecks abroad. The two ships are a reminder of Denmark’s involvement in the transatlantic slave trade, which the government banned in 1792.