Following extensive diving and archival investigations, marine archaeologists at Vrak, the Museum of Wrecks in Stockholm, have succeeded in identifying eight of nine 17th- and 18th-century warship wrecks off Karlskrona in south-eastern Sweden.
The vessels had been deliberately sunk at different times near the island of Smörasken (which gives the wreck-site its name) and lie in two neat parallel rows. Their discovery was reported on Divernet in 2022, when it was thought that the site contained 10 or more ships lying together.
One of the eventual nine was intended to act as the foundation for a pier, while the others formed an underwater blockade, part of Karlskrona’s defences against naval incursions.
Karlskrona was built on the Baltic coast in the mid-17th century to become Sweden’s biggest naval base, which it remains.
The underwater surveys were followed by tree-ring dating of crossbeam timber samples and archival research to put names to the vessels. Now the results have been presented in a comprehensive report by Vrak marine archaeologists Jim Hansson and Patrik Höglund, who led the scuba-diving investigations at Smörasken in 2022 and 2023.
“Among other things, we have identified one of the wrecks as Hercules, the oldest warship found so far in Karlskrona,” says Hansson. That warship was built in 1651.
The team have also identified “with great certainty” the Queen Ulrika Eleonora (the largest wreck at more than 50m long and already tentatively identified at an early stage), Queen Hedvig Eleonora and Uppland, all also built in the 1600s. Other ships include the Jägaren, Falken, No 17 and Sankt Peter.
“These ships were sunk in the early 18th century during the Great Northern War as part of Karlskrona’s defences,” says Höglund. “Together with other structures, they formed a protective barrier against Danish and Russian attacks.
“We can see that many ships were sunk as a quick defence because they were not equipped for an external threat,” adds Hansson. “Similar parallels can be seen today – although now we have joined NATO!”
The Smörasken investigations form part of a research programme called “The Forgotten Fleet – Sweden’s Blue Cultural Heritage 1450–1850”. This collaboration between Vrak / SMTM, the Centre for Maritime Studies at Stockholm University and the National Board of Antiquities in Finland is funded by the Riksbank’s Anniversary Fund.
Another six later blockships were discovered at Djupasund, further out from Karlskrona, and identified by the Vrak divers in 2022 before being designated to form a diver trail. The team have also discovered a 12th-century underwater “barricade forest” near Karlskrona.
“This is fantastic material that tells the story of a time when Sweden was one of Europe’s greatest naval powers,” says Hoglund of the latest study. “The finds will be an important source for both continued research and knowledge transfer.” The report (in Swedish) can be downloaded from the Vrak website.
