From the beginning it was clear that submarine flotilla was needed as the offensive part of a modern navy. Finns knew well that the best submarine designers were in Germany.

CV 707 was launched on 10 May 1933 in Crichton-Vulcan dockyard in Turku.

The vessel was the 4100-ton Vyborg on her voyage from Tallinn to the East. Aittola steered Vesikko into an ideal torpedoing position and sank the enemy.

Vesikko made her last voyage on 11 December 1944 and four days later she lowered her war banner and flag.

These charts from 1940’s show some bases and routes used by submarine Vesikko.