In World War II Vesikko was a submarine of the Finnish Navy, built by the Chrichton-Vulcan shipyard in Turku. It served as a direct prototype for German Class A II submarines.

Vesikko was one of five submarines to serve the Finnish navy. The other four were of the so-called "Vetehinen class", and consisted of Vetehinen, Vesihiisi, Iku-Turso, and Saukko.

It has since been decommissioned, as peace treaty obligations forbid the use of submarines in the military of Finland, until soviet union collapsed.

The submarine currently stands at the island fortress Suomenlinna and serves as a museum.

Technical specifications

• Dimensions
  • Length: 40.9 m
  • Width: 4.1 m
  • Height: 4.2 m
• Operational details
  • Speed: 13/8 knots (24/15 km/h)
  • Range: 1500 miles (2,400 km) at 10 knots (19 km/h) or 150 hours on the surface; submerged 50 miles (80 km) at 4 knots (7 km/h) or 13 hours.
  • Crew: 18 to 20
  • Maximum depth: 100 m.
  • Crash dive: 45 seconds to 9.3 m.
• Armaments
  • 5 torpedoes of 535 mm diameter.
  • One 20 mm Anti-Aircraft gun
  • One 12.7 mm Anti-Aircraft machine gun
• Other equipment
  • 2 MWM diesel engines of 700 horsepower (520 kW)
  • 2 Siemens electric motors of 360 horsepower (270 kW)
  • Atlas Werke 2x6 microphones as Asdic. listening devices.
• Supplies
  • 9.6 tons diesel oil.
  • 1.2 tons fresh water.