13 Land and Water Speed Records

Official underwater speed records -- usually achieved by military submarines -- are not kept due to the secrecy surrounding the capabilities of these warships. But in 1965, the USS Albacore, a Gato-class submarine, was clocked at 33 knots (38 mph), an unofficial underwater speed record. Claims of higher speeds have been made by submarine manufacturers but have not been officially measured.

­Russia's Akula-class submarine allegedly can travel at 35 knots (approximately 40 miles per hour) submerged, while the Alfa-class submarine it replaced was said to reach 44.7 knots (approximately 51.4 miles per hour) for short periods.