Greek submarine Delfin (1912)

A scale model of Delfin at the Athens War Museum
History
Greece
Name	Delfin
Namesake	Dolphin
Ordered	September 1910
Builder	Schneider Shipyards, Chalon-sur-Saône, France
Laid down	1911
Launched	1912
Commissioned	9 August 1912
Decommissioned	1920
Fate	Scrapped
General characteristics
Type	Submarine
Displacement	Surfaced: 310 tons Submerged: 460 tons
Length	47.10 meters (154 ft 6 in)
Beam	4.7 m (15 ft)
Draft	2.85 meters (9 ft 4 in)
Installed power	2 × diesel engines, surfaced 2 × electric motors, submerged
Propulsion	2 × propellers
Speed	Surfaced: 13 knots (24 km/h) Submerged: 8.5 knots (15.7 km/h)
Range	1,800 nmi (3,300 km; 2,100 mi) (surfaced) 48.8 nmi (90.4 km; 56.2 mi) at 4.5 knots (8.3 km/h; 5.2 mph) (submerged)
Test depth	36 m (118 ft)
Complement	19
Armament	1 × 450 mm (17.7 in) internal torpedo tube 4 x Drzewiecki drop collars 6 x torpedoes

Delfin (Greek: Δελφίν, "dolphin") was a submarine built for the Greek Navy in 1911. She served during the Balkan Wars, earning the distinction of being the first submarine in the world to conduct offensive patrols and launch a submerged torpedo attack (albeit without success) against a warship.

In 1916, she was seized by the Entente during the Greek National Schism. The lack of proper maintenance during the period of her confiscation led to serious structural damage. Her poor condition meant that she saw little service until her decommissioning and eventual scrapping in early 1920.