Hecht, Biber und Co.

German midget submarine "Delphin".
 

Mikro Mir # 35-004; scale: 1:35 

Without a torpedo which was attached under the fuselage. 

Only 3 boats were put into service - only prototypes at the end of war. 

Mini sub "Delphin" (dolphin). One man crew. Diving depth max. 30 m. Top speed: 10 kn (surfaced)/ 18 kn (submerged). Range: max. 300 sm.
Source: wikipedia