US Navy builds Stingray-esque base in Indian Ocean

Reports have emerged that the US Navy is upgrading its submarine base at the isolated tropical atoll Diego Garcia, which is formally British territory.

The base improvements will allow its new class of SSGN nuclear submarines to operate from Diego Garcia, which is potentially noteworthy. The tiny island group is situated in the middle of the Indian Ocean, giving the US and its allies access to various strategic maritime choke points such as the Straits of Hormuz – the entrance to the Gulf – and the pirate-plagued waters of the Bab-el-Mandeb at the foot of the Red Sea.

Perhaps even more significantly in the light of recent events, Diego Garcia is a useful base for operations off the south-eastern coastline of Iran, close to the border with the lawless frontier regions of Pakistan.

Normally, a few tens of millions of dollars in base improvements wouldn't raise eyebrows even at a critical harbour like this one. But an increased presence of SSGN subs will be well worth bearing in mind for the various military forces active in the region.

This is because SSGNs aren't your average nuclear submarine. They are converted Ohio-class Trident ballistic-missile boats, recently retired from their old job under the terms of strategic arms-limitation treaties. But the US Navy saw no reason to get rid of the submarines themselves, and the removal of the Tridents left them with plenty of room for other things.

The rebuilt vessels can nowadays carry 66 elite special-forces frogmen, who will typically be Navy SEALs or possibly members of the new US Marines MARSOC outfit. Some reports suggest that up to 102 underwater warriors may be able to cram in for short periods. The subs will have a "dry hangar", an underwater docking bay allowing the frogmen to deploy from their mother ship aboard SEAL Delivery Vehicles (SDVs), minisubs which can carry them in to enemy coastlines.

One variant of the SDV is said to be armed with its own torpedoes, though these would probably be for use against anchored ships rather than Stingray or James Bond style undersea dogfights. There has also been some suggestion that the Advanced SEAL Delivery System (ASDS) might deploy from the SSGNs. The ASDS is a larger, enclosed mini-sub which can carry SEALs in warm dry conditions rather than delivering them into battle shivering and frozen. However, reports suggest that the ASDS programme has hit problems; it may be that only a single prototype craft will be available.

Once the frogmen are in action, perhaps ashore in coastal regions, in enemy harbours or far inland by river, they won't be lacking support. A normal submarine can, of course, launch cruise missiles to attack targets inland; but the SSGNs are something special in this regard. Each sub is said to carry up to 154 Tactical Tomahawks, robot kamikaze jets which can be remotely piloted to strike locations a thousand miles inland.

The UK lags well behind the US, as ever, in the field of amazing Team America-like organisations – despite the fact that the converted Ohio boats' Marineville-esque base will be located on nominally British territory.

However, the Royal Marines' Special Boat Service frogmen are well thought of in the international underwater-scuffler community ("the SBS are as hard as woodpeckers' lips"," one SEAL once told this reporter). The British Troy Tempests are somewhat lacking on the kit front, though, with the UK possessing only a single dry hangar attached to a relatively normal mothership. As for vessels capable of carrying 60 frogmen beneath the waves for months on end, or cruise missile firepower in the hundreds, for now the SBS can only dream.

Being submarine-based, all these things can be used even against countries with fairly capable air forces and surface patrols. The presence of SSGN-type platforms in a theatre means that any large body of water connected to the sea suddenly becomes a danger, potentially full of heavily-armed SEALs or underwater robot platforms such as the Talisman.

Various people in the Indian Ocean area will be viewing the announcement of the Diego Garcia upgrades with interest. ®