Sunken Secrets Revealed: Shipwrecks Off Costa Rica Unmasked as Danish Slave Ships

A groundbreaking discovery has reshaped our understanding of maritime history and the transatlantic slave trade. Archaeologists have definitively identified two 18th-century shipwrecks discovered off the coast of Costa Rica as the remains of Danish slave ships, the Fridericus Quartus and the Christianus Quintus. The wrecks, resting in the shallow waters of Cahuita National Park, had long been a mystery, initially speculated to be the remnants of pirate vessels. However, meticulous analysis of artifacts recovered from the site, coupled with historical records, has revealed their grim purpose.

The National Museum of Denmark, which spearheaded the research, announced the findings, shedding light on a dark chapter in Danish colonial history. The two ships met their end in 1710 under dramatically different circumstances. According to museum records, the Fridericus Quartus was deliberately set ablaze, while the Christianus Quintus was wrecked after its anchor rope was intentionally severed, sending it crashing into the surf. The precise location of these shipwrecks had remained elusive for centuries, adding to the enigma surrounding their story.

The excavation of the shipwrecks, undertaken in 2023, involved a painstaking process of underwater archaeological investigation. Divers carefully documented and retrieved artifacts from the decaying remains of the vessels, which have spent over three centuries submerged in the Caribbean Sea. These artifacts included samples of the ship’s wooden structure and distinctive yellow bricks that formed part of the cargo. The discovery has prompted extensive analysis, conducted by researchers at the National Museum of Denmark and the University of Southern Denmark, to unravel the ships’ origins and purpose.

One of the key techniques employed in the investigation was dendrochronological analysis, also known as tree-ring dating. This method involved examining the patterns of tree rings in the ship’s timbers to determine the age and origin of the wood. The analysis revealed that the timber originated from the western Baltic Sea region, encompassing parts of northeastern Germany, Denmark, and southern Sweden. Specifically, the wood was traced to the provinces of Mecklenburg and Schleswig-Holstein in Germany, Denmark itself, and Scania in Sweden. Moreover, the tree rings indicated that the trees were felled between 1690 and 1695, providing a crucial timeframe for the construction of the ships.

Adding further weight to the evidence, the wooden timbers exhibited signs of charring and soot, corroborating historical accounts that the Fridericus Quartus was destroyed by fire. The archaeological team also recovered numerous clay pipes from the wrecks. These pipes, identified as ordinary Dutch-produced pipes commonly used on Danish ships, offered further clues about the ships’ identity and the time period in which they were active. The size, shape, and patterns of the pipes suggested that they were manufactured shortly before the ships’ demise in 1710. Notably, clay pipes of this type typically had a short lifespan, rarely lasting more than five years, further supporting the dating of the shipwrecks.

The distinctive yellow bricks recovered from the site provided yet another compelling piece of evidence. These bricks, produced in Flensburg, were known to be used in Denmark and its colonies during the 18th and 19th centuries. The museum noted that other European countries favored different types of bricks and stones for construction at that time, making the presence of these specific yellow bricks a strong indicator of Danish origin. Analysis of the clay used to make the bricks pinpointed its source to either Iller Strand or Egernsund, both located on Flensburg Fjord, a region that was a hub of brick production in the 18th century.

The convergence of evidence from various sources – dendrochronological analysis, the presence of charred timber, the discovery of Dutch-produced clay pipes, and the identification of Flensburg-produced yellow bricks – has led researchers to confidently conclude that the shipwrecks are indeed those of the Fridericus Quartus and the Christianus Quintus, two Danish slave ships that sank off the coast of Costa Rica in 1710.

David Gregory, a marine archaeologist at the National Museum of Denmark, emphasized the significance of the findings. He stated that the results align perfectly with historical accounts of one of the ships burning. "The analyses are very convincing, and we no longer have any doubts that these are the wrecks of the two Danish slave ships," Gregory declared. "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."

Andreas Kallmeyer Bloch, another marine archaeologist at the National Museum of Denmark, expressed his astonishment at the discovery. He admitted to nearly giving up during the lengthy research process but was ultimately thrilled by the results. "This is undoubtedly the craziest archaeological excavation I’ve yet been part of," Bloch said. "Not only because it matters greatly to the local population but also because it’s one of the most dramatic shipwrecks in the history of Denmark, and now we know exactly where it happened. This provides two pieces that have been missing from the history of Denmark."

The identification of the shipwrecks as Danish slave ships sheds light on Denmark’s role in the transatlantic slave trade, a dark period in human history. The discovery serves as a stark reminder of the human cost of this brutal trade and the importance of confronting this painful legacy. The knowledge gained from the excavation will undoubtedly contribute to a more comprehensive understanding of the transatlantic slave trade and its impact on both Europe and the Americas. The findings also highlight the importance of preserving maritime heritage and the potential for archaeological discoveries to rewrite historical narratives.