HMS P611 was a submarine of the Oruç Reis class

Oruç Reis class submarine

The Oruç Reis class submarines were ordered by the Turkish Navy from the British company Vickers in 1939. They were similar to the British S class submarines, but slightly smaller. They had the S class machinery but only four bow torpedo tubes...

 originally built for the Turkish Navy

Turkish Navy

The Turkish Navy is the naval warfare service branch of the Turkish Armed Forces.- Ottoman fleet after Mudros :Following the demise of the Ottoman Empire in the aftermath of World War I, on November 3, 1918, the fleet commander of the Ottoman Navy, Liva Amiral Arif Pasha, ordered all flags to be...

, but commissioned into the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 after the outbreak of war.

She was a modified British S class

British S class submarine (1931)

The S-class submarines of the Royal Navy were originally designed and built during the modernisation of the submarine force in the early 1930s to meet the need for smaller boats to patrol the restricted waters of the North Sea and the Mediterranean Sea replacing the British H class submarines...

 design launched on 19 July 1940 by Vickers Armstrong

Vickers Armstrong

Vickers-Armstrongs Limited was a British engineering conglomerate formed by the merger of the assets of Vickers Limited and Sir W G Armstrong Whitworth & Company in 1927...

 at Barrow. Due to the pressing need for her, she was commissioned into the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 on 1 December 1941 so she could be sent to Turkey

Turkey

Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

. It was not until 26 March 1942 that she left the Clyde

River Clyde

The River Clyde is a major river in Scotland. It is the ninth longest river in the United Kingdom, and the third longest in Scotland. Flowing through the major city of Glasgow, it was an important river for shipbuilding and trade in the British Empire....

 for Gibraltar

Gibraltar

Gibraltar is a British overseas territory located on the southern end of the Iberian Peninsula at the entrance of the Mediterranean. A peninsula with an area of , it has a northern border with Andalusia, Spain. The Rock of Gibraltar is the major landmark of the region...

. On April 7 she left Gibraltar for Alexandria

Alexandria

Alexandria is the second-largest city of Egypt, with a population of 4.1 million, extending about along the coast of the Mediterranean Sea in the north central part of the country; it is also the largest city lying directly on the Mediterranean coast. It is Egypt's largest seaport, serving...

, where she arrived on April 25. She arrived at the Turkish naval base at İskenderun

Iskenderun

İskenderun is a city and urban district in the province of Hatay on the Mediterranean coast of Turkey. The current mayor is Yusuf Hamit Civelek .-Names:...

 on 9 May 1942 and was handed over to the Turkish Navy. She would continue in service with the Turkish Navy, operating against Axis forces in the Mediterranean, and remained in service after the war ended. She was finally broken up in 1957.