Diving was performed with the flood ports closed and the vent valves open, in order to prevent a negative inclination from the inflow of water in the bow and stern ballast tanks.

[4] For surface running, the boat was powered by two Schneider-Carels diesel engines which were heated by compressed air for 10-15 minutes by their corresponding two electric motors before starting.

[1][2] The Hellenic Navy underwent a major reorganization and rearmament in the aftermath of the 1909 Goudi coup.

Thus submersible Delfin and its sister ship Xifias were ordered from the Schneider Shipyards at Chalon-sur-Saône, France in September 1910.

[8] The French news-photograph concern Agènce Rol produced a series of photographs of Xifias undergoing diving and submerged torpedo-firing tests off Toulon in June 1913.

Like its sister ship, Xifias was plagued by mechanical problems and had insufficient operational capabilities; as a consequence, its use was minimal in the years that followed.

[8] A second vessel of the Hellenic Navy has received the name Xifias: the British U-class submarine HMS Untiring, which was leased to Greece in 1945–1952.