>" The Defense Ministry has ordered a total of six Varshavyanka-class subs,
dubbed "black holes in the ocean" by the US Navy because they are nearly undetectable when submerged..."<
Russia
>"The Project 636 Kilo-class submarine has been dubbed the “black hole” by the U.S. Navy for its level of quietness. The Project 636MV-class sub has improved stealth features through the removal of flooding ports and treating the hull with multilayer anechoic rubber tiles. The tiles are fitted on casings and fins to absorb active sonar waves that reduce and distort the return signal. The anechoic tiles also shield sounds from within the submarine thus reducing the range of detection by passive sonar.
The improved Kilo is 73.8 meters (242 ft.) in length, 9.9 meters (32.4 ft.) in width with a draft of 6.2 meters (20.34 ft.). It has a surface displacement of 2,350 tons and can dive up to quarter of a mile. The improved Kilo is powered by diesel-electric engines. It has a range of 9,650 km (5,996 miles) and can travel
700 km (434 miles) underwater at 2.7 knots (5 km/hour) at quiet speed. The Kilo can reach a top speed of 20 knots (37 km/hour). Vietnam apparently has not opted for the Air Independent Propulsion system that would permit extended time on patrol. The Improved Kilo has a crew of 57.
The Project 636MV submarine has six 533-mm forward torpedo tubes. It can carry 18 torpedoes (six loaded in the tubes and 12 in racks) or 24 mines (two in each tube and 12 in racks). Two of the torpedo tubes are designed to fire remote-controlled torpedoes with very high accuracy. The improved Kilo can also fire anti-ship cruise missiles from its torpedo tubes. The Kilo also carries MANPADS Strela-3 antiaircraft missiles..."<
Russian Subs in Vietnam - USNI News