Circé was the lead boat of her class of two submarines built for the French Navy in the first decade of the 20th century.
Design and description
The Circé class were built as part of the French Navy's 1904 building program to a double-hull design by Maxime Laubeuf. The submarines displaced surfaced and submerged. They had an overall length of, a beam of, and a draft of. Their crew numbered 2 officers and 20 enlisted men. For surface running, the boats were powered by two German MAN diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a electric motor. During her surfaced sea trials on 19 September 1908, Circé reached a maximum speed of from ; during her submerged trials on 25 June 1909 she reached from. The Circé class had a surface endurance of at and a submerged endurance of at. The boats were armed with six external torpedo launchers; four of these were fixed outwards at an angle of five degrees, two firing forward and two firing to the rear. The aft tubes were reversed in March 1911 so they too fired forward. The other launchers were a rotating pair of Drzewiecki drop collars in a single mount positioned on top of the hull at the stern. They could traverse 150 degrees to each side of the boat. A support for a deck gun was ordered to be installed on 29 March 1911, but the gun itself was never fitted.
On 29 April 1915, Circé made several attempts to penetrate the harbour of Cattaro. Finally she gained entrance, but found no targets and had to retire. On 31 March 1917 in the Adriatic Sea, she launched a torpedo towards the German submarine, but missed. On 24 May 1917, under command of Lieutenant Hélion De Cambourg, she succeeded in sinking the German submarine. This was one of the few sinkings by a French submarine during World War I. On 20 September 1918, Circé under command of Lt. Henri Viaud was on anti-submarine patrol in the Southern Adriatic Sea, off Cattaro, when she was torpedoed by the Austro-Hungarian Navy submarine at 04:00, while recharging her batteries. Only one survivor was rescued.