UB-II class submersibles

UB-2 class (1915-18) German Empire – 30 submarines, UB-18 to UB-47 UB-45 underway in 1916 The UB-II class. Second part

Type II U-Boat

German Type UE II submarine - Wikipedia

U-boat - Wikipedia

UB-1 class submersibles (1914)

UB-II class submersibles

What was the fastest submarine in World Wars 1 and 2? - Quora

Submarines at War: From the Turtle to U-boats, Nuclear Submarines, and Unmanned Systems

Teaching of the class in the course of Decommissioning and Dismantling of Ships and Offshore Assets, promoted by IPETEC – Instituto de Pesquisa Educação e Tecnologia. – TechCon

H I Sutton on X: Royal Navy N-class submarine HMS Nautilus from #WW1. As far as I can find in my research, she was by far the largest submarine in the world

UB-1 class submersibles (1914)