Alligator was a submarine designed by the French that was deployed during the American Civil War by the Union. It was 47 feet long and four feet in diameter. ¹⁾.

With a submerged displacement of 48,000 tonnes, a length of 574ft (175m) and a beam of 75ft (23m), Project-941 Akula class (NATO reporting name Typhoon) nuclear-powered submarines are the largest ever made²⁾. They could reach 27 knots (50km/h) while submerged and stay underwater for over 120 days.

They could carry 20 R-39 ballistic missiles³⁾, each with 10 nuclear warheads. This means that each (of the six ever built) Typhoon-class submarines were able to sneak to almost any place in the world undetected and launch nuclear warheads to 200 separate targets in a 5,200-mile (8,300 km) range in a short period of time. With a blast yield of 100-200 kt of TNT each⁴⁾ (which is 10 times more powerful than the atomic bombs used in Hiroshima and Nagasaki), they were capable of annihilating entire countries.

Today only one Akula, TK-208 Dmitry Donskoy, remains in service⁵⁾.