https://naval-encyclopedia.com/ww2/finland/vetehinen-class-submarines.php
Vetehinen class submarines (1930)
The Vetehinen class were the first (minelayer) Finnish submarines (1930), based on improved WW1 UB-III/UC-III designs by I.V.S. at the Hague.
vetehinenclasssubmarines
https://www.5thwrist.com/suf-vetehinen-review/
Owner Review: S.U.F Vetehinen - Not for Everyone -
owner reviewufvetehineneveryone