Finnish submarine Vesikko

History
Finland
Name	Vesikko
Ordered	9 October 1930
Builder	Crichton-Vulcan
Laid down	7 March 1931
Launched	10 May 1933
Commissioned	30 April 1934
In service	19 January 1936
Out of service	1946
Status	Museum ship
General characteristics
Type	Coastal submarine
Displacement	254 t (250 long tons) surfaced 303 t (298 long tons) submerged 381 tonnes total,
Length	40.90 m (134 ft 2 in) o/a 26.10 m (85 ft 8 in) pressure hull
Beam	4.076 m (13 ft 4.5 in) 4.026 m (13 ft 2.5 in) pressure hull
Height	8.18 m (26 ft 10 in)
Draft	3.79 m (12 ft 5 in)
Propulsion	Diesel-electric, 2 diesel engines each 350 PS (257 kW; 345 bhp) 2 double-acting electric motors each 180 PS (132 kW; 178 shp)
Speed	13 knots (24 km/h; 15 mph) surfaced, 8 knots (15 km/h; 9.2 mph) submerged
Range	1,350 nmi (2,500 km; 1,550 mi) at 8 knots surfaced, 40 nmi (74 km; 46 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth	150 m
Complement	4 officers, 8 non-commissioned officers, 4 enlisted
Sensors and processing systems	2 × 6 Atlas Werke hydrophones, 1 receiver station (Gruppenhorchgerät)
Armament	3 × 53.3 cm (21 in) torpedo tubes in the bow 5 torpedoes 1 × 20 mm (0.79 in)/60 Madsen AA gun 1 × 12.7 mm (1 in) machine gun

Vesikko is a submarine, which was launched on 10 May 1933 at the Crichton-Vulcan dock in Turku. Until 1936 it was named by its yard number CV 707. Vesikko was ordered by a Dutch engineering company Ingenieurskantoor voor Scheepsbouw (a German front company) in 1930 as a commercial submarine prototype, being the prototype for the German Type II submarines. Purchased by the Finnish before World War II, she saw service in the Winter War and Continuation War, sinking the Soviet merchant ship Vyborg as her only victory. After the cease-fire with the Allies in 1944, Vesikko was retired. Finland was banned from operating submarines after the war and she was kept in storage until she was turned into a museum ship.

Vesikko was one of five submarines to serve in the Finnish Navy. The other four were the three larger Vetehinen-class boats Vetehinen, Vesihiisi, Iku-Turso and the small Saukko. The word "vesikko" is the Finnish name for the European mink.