56.152056°N 15.169556°E / 56.152056; 15.169556

The 1st Submarine Flotilla (Swedish: Första ubåtsflottiljen, 1. ubflj) is a unit of the Swedish Fleet which has operated in various forms since 1904. Its unit staff is located at Karlskrona naval base, Blekinge in Karlskrona Garrison.^[4][5]

The embryo of the 1st Submarine Flotilla was formed in 1904, when the Swedish Navy was supplied with its first submarine, Hajen, and the submarine force was formed.^[6] In 1918 the submarine force was included as the 1st Submarine Division (1. undervattensbåtsdivisionen) in the Coastal Fleet. In 1934, the submarine force had been organized as the Submarine Department (Ubåtsavdelningen) with three included divisions. In 1951, the unit was assigned its current name, and was part of the Coastal Fleet as the 1st Submarine Flotilla. During the 1970s, the Navy Diving School (Flottans dykarskola) was added to the flotilla, which later formed the Diving Division (Dykdivisionen), which included submarine rescue ships.

On 1 July 1994, the flotilla was organized as the First Submarine Department (Första ubåtsavdelningen, 1. UbA). This because all units within the Swedish Armed Forces were cadre organized, and got a permanent organisation. On 1 January 1998, the flotilla received its current name 1st Submarine Flotilla (Första ubåtsflottiljen, 1. ubflj), and by the Defence Act of 2004 it was decided that the flotilla with its staff would be relocated from Hårsfjärden to Karlskrona. From 1 January 2005, the flotilla came to serve from Karlskrona naval base.

Between 1904 and 1998, the submarine force was included in the Coastal Fleet. See below the composite of the submarine force at different time points. During the 1930s, the submarine force was included in the Winter Squadron (Vintereskadern), which was the equipped part of the Swedish Navy during winter time. Parts of the submarine force were included in the Gothenburg Squadron and the Karlskrona Department (Karlskronaavdelningen) during World War II.^[7]