Koster (MCC)

The Koster class is a series of mine countermeasures vessels, an upgraded version of the Landsort class, originally developed and built in Sweden. These vessels are designed for mine hunting and sweeping operations, utilizing advanced sonar and remotely operated vehicles.

Initiated in 2004, the Koster-class modernization program was launched by the Swedish Defence Materiel Administration to upgrade five existing Landsort-class hulls with modern combat management systems and improved self-defense capabilities. The upgraded vessels, led by HMS Koster, began re-entering service with the Swedish Navy in 2009. While they have not seen active combat, the class has been heavily utilized in multinational Baltic Sea exercises like BALTOPS and routine operations to clear historical World War-era naval mines. Today, all five vessels remain active within the Swedish Navy's 4th Naval Warfare Flotilla, serving as a cornerstone of Sweden's shallow-water maritime security.