Class overview
Name	Sisu
Builders	Fratelli Orlando, Livorno, Italy
Operators	Finnish Navy
Succeeded by	Isku class
Built	1916
In commission	1922–1942
Completed	2
Retired	2
General characteristics
Type	Motor torpedo boat
Displacement	13 tons
Length	16.2 m (53 ft 2 in)
Beam	3 m (9 ft 10 in)
Draught	1.2 m (3 ft 11 in)
Propulsion	2 × Isotta Frachini; 373 kW
Speed	25 knots (46 km/h; 29 mph)
Range	150 nmi (280 km; 170 mi)
Complement	7
Armament	2 × 450 mm torpedoes 1 × machine gun 4 × depth charges 2 × mines

The Sisu-class motor torpedo boats (English: Guts) was a series of two Italian MAS type motor torpedo boats of the Finnish Navy. The vessels were constructed in 1916 by the Orlando shipyard in Livorno, Italy. Sisu and Hurja were purchased by the Finns in 1920, and saw service in World War II.^[1] When dashing forward at full speed, the vessels sprayed water high in the air, earning the nickname "the fountains" from Finnish sailors.

On 1 October 1941 Sisu, together with Nuoli, was patrolling east of Gogland when it came across a large, stationary Soviet minesweeper of the Fugas class. Sisu missed with her first torpedo, having mistaken the foam painted on the minesweeper's bow for an indication that it was actually moving. A second torpedo hit the minesweeper amidship and sank her.^[2]

Vessels of the class

Sisu

Ex-MTV 1 in Finnish service, and ex-MAS 220 in Italian service. She was used as a torpedo boat until 1942, and then transferred to Lake Ladoga, where she served as a patrol vessel. Sisu was broken up after the war.^[1]

Hurja

Ex-MTV 2 in Finnish service, and ex-MAS 221 in Italian service. She was used as a torpedo boat until 1941. Hurja was broken up after the war.^[1]