Specifications. The improved model has a quieter motor than boats “Bars”, so it is a very low noise boat in the Russian fleet. 971 submarine’s speed is 10 knots (at a depth of 600 meters it can reach speeds up to 33 knots). It is equipped with various anti-submarine, anti-aircraft and anti-ship weapons, including 12 cruise missiles “Granit”, torpedoes and MANPADS.