Up close the islands are hardly more impressive than the dots on the charts on the bridge of the Illustrious - a collection of 230 shoals, spits and reefs spread over 180,000 square kilometres of the South China Sea.
In photographs, the Spratlys resemble the archetypal cartoon desert- island-with-palm-tree, with occasional huts on stilts built as as shelters for passing fishermen.
But the impression of isolated obscurity is misleading. In a region that has more than its share of disputed islands, the Spratlys are the most disputed of all, a stubborn source of tension which is looking more and more like a serious obstacle to peace in the region.
Unlike the bilateral disagreement over the Kurile Islands (Russia and Japan) or the trilateral one over the Senkaku/Diaoyu group (Japan, China and Taiwan), the Spratly problem is a six-way dispute.
Nineteenth-century British sailors may have named the islands, but the dispute over their ownership is an exclusively Asian one. China, Taiwan and Vietnam claim the entire group; Brunei, Malaysia and the Philippines claim parts of it.
There are some 40 military garrisons on the islands, more than half of them Vietnamese, and all the claimants, apart from Brunei, have at least one airstrip. Several times a year, the simmering diplomatic tension between the rivals bubbles up into a physical stand off; only last week, Peking accused Manila of violating Chinese sovereignty after Filipino fishermen hoisted a flag over the shoal, and a group of congressmen sailed there and asserted Philippine sovereignty.
In several ways the dispute looks like a model for the new kind of conflict which is likely to plague East Asia over the next few decades. Unlike Asia's Cold War flashpoints, there is no ideological dimension to the dispute. Apart from the garrisons, the Spratlys have no native population to be be won over to one political system or another. The struggle now being waged is for control, not of people, but of resources in the fastest growing, energy-poorest region in the world.
A quarter of the world's shipping passes through this area every year - the Spratlys' position in the middle of the South China Sea thus gives the islands an obvious strategic importance. The narrow sea lanes of south- east Asia link the established markets of Europe with the fastest growing economies in the world. Seventy per cent of oil consumed by Japan, Korea, China and Taiwan is tankered through here from the Middle East, a proportion likely to increase to 95 per cent by 2010.
The secret hope of Spratly claimants is that the islands contain large reserves of oil, or at least of natural gas. Surveys so far have been limited and inconclusive. But the islands certainly have ample living resources. Half the world's fish supplies are caught in Asia, but growing demand and dwindling stocks are increasing competition between nations. The area around the Spratlys is rich in fish, an important consideration for countries like China and Indonesia, with growing populations, but limited arable land.
Nor is this just a local problem. South-east Asia's rising status as the fastest economic growth area of the 21st century makes the area's peace and security an international concern, and does much to explain the presence of the Illustrious.
"We're still one of the largest trading nations in the world," said a senior officer on the ship, "and this is undoubtedly the area of the greatest economic growth. We'll be passing close enough that all the countries interested in the islands will know we're there, and we'll be making a statement by passing through."
Diplomatic efforts to solve the problem have made little progress, but, militarily, much is happening. The navies of south-east Asia have in the past limited themselves to coastal patrol work. All that is quickly changing.
Last week, a couple of Thai admirals visited HMS Illustrious for tips on how to use their own new aircraft carrier, an acquisition which the Chinese are also believed to be planning; Singapore now has a submarine.
General Arnulfo Acedera, the Philippines military chief, was asked yesterday whether there was a risk of an armed confrontation over the islands.
"The possibility is there," he said, adding, bluntly: "That's why it's called a flashpoint."Reuse content