She was commissioned in 1931, ahead of Germany's first purpose-built submarine tender, Saar.

Constanța was laid down in August 1927 at the Italian Quarnaro Shipyard in Fiume, being completed in 1931.

[2][3] At the start of Operation Barbarossa in June 1941, Constanța was the flagship of the Grupul submarine și vedete torpiloare (The submarines and motor torpedo boats group), the only formation of the Romanian Navy designated for offensive operations.

The group also comprised the submarine Delfinul and three motor torpedo boats of the Vospers type (Viscolul, Viforul and Vijelia).

[6] On 28 August 1944, she was captured by Soviet forces and, unlike most other warships of the Romanian Navy, was never returned.