German submarine U-158 was a Type IXC U-boat of Nazi Germany's Kriegsmarine built for service during World War II.
U-505, a typical Type IXC boat
Deck gun
Videos
A deck gun is a type of naval artillery mounted on the deck of a submarine. Most submarine deck guns were open, with or without a shield; however, a few larger submarines placed these guns in a turret
British Mk XXII 4-inch deck gun from S-class submarine
5"/25 caliber gun on the deck of Balao-class submarine USS Bowfin
Bofors 102 mm/4-inch naval gun from the Romanian submarine Delfinul