HMS H6

HMS H6, was a British H-class submarine of the Royal Navy built by Canadian Vickers & Co. during World War I.

History
She was completed on 10 June 1915 and was commissioned by the Royal Navy the same year. However, her service in the Royal Navy was short. On 19 January 1916 she ran aground near the Dutch island of Schiermonnikoog after which she was interned by the Dutch Navy. On 4 May 1917 an agreement was reached to sell H6 to the Netherlands.

Dutch service
The Dutch Navy renamed the H6 to Hr.Ms. O 8 and refitted her with knowledge gained from the interned German submarine SMU UC-8. After UC-8 was bought from Germany the O 8 was equipped with the SMU UC-8's Zeiss periscope. During maintenance in October 1921, O 8 sank in the harbour at Den Helder. Because only minor damage was sustained, she was repaired and continued service. In the summer of 1925 O 8 together with the HNLMS K XI, HNLMS Jacob van Heemskerck (1906), HNLMS Maarten Harpertszoon Tromp, HNLMS Z 3 and HNLMS Z 5 were part of an exercise in the Baltic Sea.

During the German attack on the Netherlands at the start of the Second World War the O 8 was still in Dutch service. Because of her old age it was decided to scuttle her.

German service
After the surrender of the Netherlands the German forces were able raise the O 8 and found her almost fully intact.

Germany took the O 8 into service as U-D1 and transferred her from Den Helder to Kiel. In Kiel she was used as training ship to train crews for the German U-boats. Because of her old age she was decommissioned on 23 November 1943. On 3 May 1945, she was scuttled in the harbor at Kiel.