This post totals up the number of currently operational ballistic missile submarines and their submarine-launched ballistic missile (SLBM) tubes.* These boats are mostly equipped with nuclear-armed missiles with Multiple Independently targetable Reentry Vehicle (MIRV). Missile boats or “boomers” are a premier strategic deterrence – as opposed to land-based stationary missile sites, they are difficult to target in any first strike and so present a potent retaliatory threat. Follow the links to see other submarines.
NATO Allies – 464 MIRV SLBM tubes:
United States Navy – 14X24 Ohio class SSBN LOA 560′ / 170.7 m TDISP 18,750 tons submerged
Royal Navy – 4X16 Vanguard class SSBN LOA 492′ / 150 m TDISP 15,900 tons
French Navy – 4X16 Triomphant Class SSBN LOA 453′ / 138.1 m TDISP 14,350 tons submerged
Russia – 192 MIRV SLBM tubes:
5X16 Borei Class / Project 955 SSBN LOA 557′ / 169.8 m TDISP 24,000 tons submerged
6X16 Delta IV Classes / Project 667BDRM Delfin 1X16 Delta III / Project 667BDR Calmar SSBN LOA 520′ / 158.5 m TDISP 18,200 tons submerged
China – 72 MIRV SLBM tubes:
6X12 Type 094 / 094A (NATO: Jin class) SSBN LOA 443’/ 135 m TDISP 11,ooo tons submerged
India – 24 SLBM tubes
2X12 Arihant class SSBN LOA 364′ / 110.9 m TDISP 6,000 tons. Currently armed with short or intermediate-range missiles that do not break down into MIRVs.
North Korea 1 or 2 short-ranged SLBM tubes
1X1 OR 1X2 Simpo / Gorae class SSB (Ballistic missile conventionally powered submarine) (1 active) LOA ca. 225′ / 68.6 m TDISP 1,600 tons submerged (estimate). SLBM missiles, based on observed tests are short-ranged and do not break down into MIRVs.
*At any given time, several of these boats will be undergoing dockyard work. This list does not include submarines reported to be test beds, such as the last Russian Typhoon class, Dmitriy Donskoy, or the Chinese Type 032/Qing class.
Here and at several other sites, dredging and dumping fill radically transformed mostly submerged chains of reefs into new territory, which was quickly militarized – complete with port facilities, substantial airstrips, and missile defences. 
A powerful fleet is emerging from the mists of the South China Sea. Led by a pair of carriers, in line ahead, cruisers, destroyers, frigates, amphibious assault ships, landing ships and other units are being systematically identified and logged in the Shipsearcher Database by Ship Identification Directorate (SID) staff.
The Searchers 