How Fast Is Nuclear Submarine?

Modern nuclear submarines cruise at 80 km/h underwater. The 1969 Soviet K-162 still holds the underwater speed record at 82 km/h — though running at that speed was so loud it could be heard across an entire ocean. Modern subs can stay submerged for 90 days at a stretch.

Modern nuclear submarines can stay submerged for 90+ days — limited by food storage rather than fuel or air. Their reactors run for the boat's entire 30-year service life on a single fuel load.

• Same as motorway driving
• Soviet record from 1969 still stands