Archaeologists have confirmed that two mysterious shipwrecks off Costa Rica’s coast are Danish slave ships from the 18th century, revealing a dark chapter of colonial history through advanced scientific analysis.
At a Glance
- Marine archaeologists identified two shipwrecks near Cahuita National Park as the Danish slave ships Fridericus Quartus and Christianus Quintus from 1710
- Scientific testing confirmed the ships’ wood originated from Northern Europe and was harvested between 1690-1695
- Distinctive yellow Danish bricks, charred wood, and Dutch-made clay pipes provided key evidence for identification
- One ship was deliberately set ablaze while the other had its anchor line cut, causing it to wreck in the surf
- The discovery provides significant historical insights into Denmark’s role in the transatlantic slave trade
From Mysterious Wrecks to Historical Confirmation
Two shipwrecks long submerged off the coast of Costa Rica’s Cahuita National Park have finally revealed their identities. Initially thought to be pirate vessels, recent excavations conducted in 2023 by marine archaeologists from the Viking Ship Museum and the National Museum of Denmark have confirmed them to be Danish slave ships from the early 18th century. Through meticulous investigation, researchers identified the wrecks as Fridericus Quartus and Christianus Quintus, slave-trading vessels that met tragic ends in 1710.
“The analyses are very convincing and we no longer have any doubts that these are the wrecks of the two Danish slave ships”, said David Gregory.
The underwater excavation was conducted as part of Denmark’s National Museum’s research center, Njord. David John Gregory, leading the project, employed dendrochronological testing on wood samples recovered from the ships.
These tests revealed that the timber originated from the western Baltic Sea region, encompassing northeastern Germany, Schleswig-Holstein, Denmark, and Scania, with trees harvested between 1690 and 1695 – perfectly aligning with the ships’ construction timeline.
Marine Archaeologists from the Viking Ship Museum and the National Museum of Denmark will be diving down to the remains of two ships off the coast of Costa Rica. The investigation seeks to determine whether these are the wrecks of two 18th Century CE, Danish slave ships.
Marine… pic.twitter.com/zrFrfmVfro
— Archaeo – Histories (@archeohistories) June 25, 2024
Compelling Evidence From the Deep
The breakthrough in identification came after archaeologists discovered distinctive yellow bricks at the wreck sites. These bricks, produced in Flensburg specifically for use in Denmark and its colonies, triggered deep interest in the wrecks’ potential Danish origins. The clay used in these bricks was sourced from Denmark itself, specifically from either Iller Strand or Egernsund, providing a direct material link to Danish manufacturing processes of the period.
“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 burned”, Gregory said.
Further supporting evidence came from Dutch-produced clay pipes found at the site, which date to just before the 1710 shipwreck. The discovery of charred timbers also corroborated historical records describing how one of the ships met its fate. According to these accounts, Fridericus Quartus was deliberately set ablaze, while Christianus Quintus faced a different but equally tragic end when its anchor rope was cut, causing the vessel to wreck in the coastal surf.
Advanced Documentation Techniques
The research team employed cutting-edge documentation methods to thoroughly record the wreck sites. Photogrammetry allowed them to create comprehensive digital models of the entire excavation area, providing unprecedented detail for analysis and future reference. By digitally assembling thousands of underwater photographs, researchers captured every visible aspect of the submerged wrecks in their current state of preservation.
Historical Context and Significance
According to historical records, the two Danish ships departed Copenhagen in 1708, stopping in West Africa before heading to Saint Thomas in the Danish West Indies. Both vessels were part of Denmark’s active participation in the transatlantic slave trade, which the country did not ban until 1792, with slavery itself continuing in Danish territories until 1847. The identification of these wrecks provides tangible evidence of this dark historical period.
The collaborative nature of this archaeological project, involving institutions from both Denmark and Costa Rica, highlights the international significance of these findings. Beyond simply identifying shipwrecks, this research illuminates Denmark’s historical role in the transatlantic slave trade and enhances scholarly understanding of maritime colonial history. For local populations in Costa Rica and descendants of those affected by the slave trade, these discoveries represent important physical connections to a painful shared history that continues to resonate in modern society.
