The X-class was a 4-man midget submarine built for the British Royal Navy between 1943-44. You can read more about its history at the Wiki entry link below.

Until 1959, the Triton, one of the first-generation Nuclear subs was the longest, and the first US submarine to have two independent reactors. She measured 447 ft 6 in (136.40 m) overall.

Then, the longest current class of submarine, the Ohio-class, at 560 ft (170 m), was built, and is now the longest submarine in the US Navy.

Beluga class submarine was created in 1988.

The Kursk was an Oscar II class submarine, of the Russian Navy.

Virginia class