The submarine's captain, Commander David Vaughan, says it is a 'pathfinding' visit - the frontier of submarine operations - to develop tactics for operations in warm waters very different from the Atlantic to which Cold War strategy and the Soviet threat confined British nuclear submarines.
Commander Vaughan stressed the visit was not specially connected with the arrival of Iran's first conventionally powered Kilo-class submarine at Bandar Abbas across the Gulf, where its crew are being trained. However, the Gulf states regard the presence of the British submarine as 'reassuring'. Two more Kilos are being built by the Russians in the Baltic.
It has also been confirmed that the Iranians are now building midget submarines. These are not regarded as a serious threat to shipping in the Gulf, which carries one-third of the world's oil, but more as a hazard similar to the fast motor boats used by Iranian Revolutionary Guards in the 1980s. The Iranians have not, so far, shown any reaction to the British submarine's arrival at the weekend.
HMS Triumph looked surprisingly small alongside its jetty at Abu Dhabi yesterday, a small part of her black hull - covered with foot-square anechoic tiles to absorb enemy sonar - visible above the bright Gulf waters. The newest of the Royal Navy's nuclear-powered hunter-killer submarines commissioned in 1991, she is 280ft long and displaces 5,200 tons of water when submerged.
'In this great modern port we're just a spot on the jetty but when we came in we were very visible,' said Cdr Vaughan, 37. The submarine came through the Straits of Hormuz on the surface but Cdr Vaughan said that there were 'no real problems' in operating a nuclear-powered attack submarine in these waters. It is a conventional submarine that has some problems. It has continually to charge its battery and that can make it vulnerable.
Cdr Vaughan's nuclear submarine has been at sea for two months and needed no support whatever. 'We've been in the Gulf and we've had a dive out in the middle and it's fairly straightforward,' he said.
The US navy operated several nuclear submarines in the Gulf during the 1991 war, firing Tomahawk cruise missiles at land targets. The Royal Navy had nuclear submarines 'in the area' but cannot fire cruise missiles. A US nuclear submarine, USS Birmingham, is also in the Gulf.
Cdr Vaughan said a visit to Abu Dhabi had no special significance, a point endorsed by Captain Martin Macpherson, representing the Navy's flag officer submarines. 'The need to keep nuclear submarines close to home has changed,' said Capt Macpherson. 'The purchase of the Kilo- class from Russia is clearly a development. Whilst locally here the Iranian Kilo is obviously of strategic significance, similar problems exist all over the world.' There were about 300 submarines round the world, owned by 70 nations, of similar quality to the Kilo, he added.
Crd Vaughan said it would take the Iranians years before they could carry out even a one-off submarine operation, even with Russian help, and the British experience bore this out. 'It's taken us time to develop tactics to deal with these phenomena. All these countries buying diesel submarines - it's going to take them time to work up that expertise. We're still learning.'
HMS Triumph had 123 men on board yesterday - its complement of 97, plus trainees. Each has a bunk, a locker and small curtains for privacy. The most spacious expanse is the silver and grey operations room, divided into key areas: sonar; control of weapons; navigation; and overall battle management.
The green blips on the black screens formed a maze of high technology light. The Iranians have nothing like it and it would take them 10- 15 years to develop the ability to conduct more than the occasional kamikaze operation with submarines.