The O 12-class submarine consisted of four submarines built for the Royal Netherlands Navy. The ships, with a diving depth of 60m (200feet), were used for patrols in the Dutch home waters. The class comprised O 12, O 13, O 14 and O 15. O 12 entered German service in 1943 as UD-2.
The ships were built by two shipyards. O 12, O 13 and O 14 were built by Koninklijke Maatschappij De Schelde in Vlissingen and O 15 in Rotterdam at Fijenoord shipyard.
| Name | Laid down | Launched | Commissioned | Decommissioned |
|---|---|---|---|---|
| 20 October 1928 | 8 November 1930 | Dutch Navy: 20 July 1931German Navy: 30 January 1943 | 6 July 1945 (scuttled) | |
| 1 December 1928 | 18 April 1931 | 1 October 1931 | 13 June 1940 | |
| 29 December 1928 | 3 October 1931 | 4 March 1932 | 26 June 1943 | |
| 3 March 1930 | 27 May 1931 | 28 July 1932 | 1 September 1945 | |