His colleagues wear identical black uniforms, combat boots and baseball caps, with a badge depicting the outline of the islands on their breast pockets. Their numbers are presently augmented by a team of workmen, who are renovating accommodation units atop the island known as Dong-to, alongside a watch tower, communication facility and helicopter landing pad.

A steep set of steps, in places carved from the rock, leads to the top of the 99-metre peak, passing a series of five grave markers of Koreans who have died in accidents in the 54 years since Seoul began stationing guards there.

Physically a hardship posting, with the police rotating off the island every three months, 23-year-old Captain Kang is reluctant to reveal the armoury at their disposal to repel any uninvited vessel that approaches closer than the 15 nautical mile limit, but he said his colleagues were nearly all volunteers.

'This is a very important area and we are young and curious,' he said. 'I am doing my duty by working for my country and that gives me a real sense of pride.'

He said that since the island was opened to day-trippers last year, there had been some Japanese who made the journey.

Captain Kang said he was 'confused and upset' by Tokyo's claims to the island but hoped that the two could get along. However, with the war of words over sovereignty of the rocks heating up, it appears that hope is a forlorn one for the immediate future.

'This topic has been here for many years, but it really only became amplified when the prefectural government of Shimane prefecture last year declared February 22 as Takeshima Day and the South Korean side reacted quite astonishingly,' said Akira Chiba, a spokesman for the Ministry of Foreign Affairs in Tokyo. 'Their response is the origin of the most recent problems between the two governments.'

Tokyo did not approve of the local government's move, although 35 of the 38 members of the prefecture's assembly supported the proposal on the grounds that it would promote new interest in reasserting Japan's claims to the islands, which are more than 200km off mainland Japan and about 160km from Okishima. The date chosen coincided with the day in 1905 when the prefecture issued Notice No40, announcing the incorporation of the islands into the prefecture.

The reaction last year - which had been declared a 'friendship year' between the two countries - was the cancellation of a series of exchange programmes and the postponement of a trip to Japan by Ban Ki-mun, South Korea's minister of foreign affairs and trade.

Both sides have produced reams of historical documents and maps dating back hundreds of years to support their claims on the islands, which are separated by a 110-metre-wide channel.

Dong-to and Song-to - which rises to 174 metres above sea level - and 33 rocks and reefs in the surrounding waters have been known by various names through the centuries. Usando, Sambongdo, Gajido and Seokdo to Koreans translates to Matsushima and Riyangkoto in Japanese, as well as Liancourt Rocks, named after the French whaling ship that was the first western vessel to chart their position, in 1849.

Nestled at the base of steep cliffs across the channel from the pier where tourists sometimes arrive, is the home of fisherman Kim Seong-do, 66, and his sprightly 68-year-old wife, Si-yul. Their small fishing boat is securely fastened on the slipway against the waves and Mrs Kim's hair is still wet from diving for sea urchins and shellfish.

'We have lived here for 40 years now and we make a living from the sea, selling the fish and shellfish to the island of Ulleungdo,' Mr Kim said.

'When we first arrived there were about 15 people, but we're the only ones left now. We sent our three children to the mainland for their schooling and they have stayed there, but I can't say that we get lonely, not after all these years.

'We have a television and a regular phone line was installed a couple of months ago, so we can speak to the children and the grandchildren,' he said. 'I guess I get off the island a couple of times each year, if I have to see the doctor on Ulleungdo.'

Tokyo is basing its claim on two key elements. First, the ministry said, Japan's proclamation in 1905 that the islands were Japanese territory was not met with a rebuttal from Korea, even though Korea was not yet under Japanese colonial rule at that time. Secondly, Tokyo said that after Japan's second world war defeat in 1945, Korea asked the occupation authorities in Japan to declare Tok-to to be Korean territory, but was rebuffed by the occupying government on the grounds that there was no evidence to support the claim.

South Koreans express a certain amount of national pride at getting one over on a long-term rival and their former colonial master. Bumper stickers in east coast towns proclaim Tok-to as an integral part of the homeland, the largest ship in the 300-strong Korea Coast Guard - the 6,350-tonne Sambong 3 - takes its moniker from an ancient name for the islands that means three peaks, and telephone cards bear the islands' profile, along with suitably nationalistic slogans.

Perhaps the only area that the two sides agree upon is that the issue of different names is causing problems, according to Lee Seok-woo, a professor of law at Incheon's Inha University and an authority on territorial and border disputes. But that does not change the fact that Korea has exercised sovereignty over Tok-to since AD512, interrupted only by Japan's 1905-45 occupation of the peninsula.

Professor Lee has an extensive collection of maps to support Seoul's claims to the islands, including a 1785 plan by Japanese cartographer Shihei Hayashi, on which the islands are marked as 'belonging to Korea'. He also cites the hand-written note from March 20, 1877, bearing the prime minister's seal confirming Tok-to belonged to Korea on the grounds that the islands 'are irrelevant to Japan'.

Until recently, Seoul had been happy to avoid mention of the issue because of what Professor Lee described as the 'my wife theory'.

If a neighbour claims a man's wife as his own, so the theory goes, there is no need for the husband to publicly argue the point as that merely serves to inflame a situation and perhaps legitimise a claim that onlookers know to be groundless. 'That school of thought tried to lower the tensions, but the Japanese approach has been aggressive and, instead, heightened tensions, so now some people say we have to declare our position and be more resolute,' he said.

South Korea's position on the islands is weakened by its refusal to agree to the Japanese proposal to take the dispute to independent arbitration, such as the International Court of Justice in the Hague.

'In all the outstanding territorial disagreements around the world, this one is historically unique because it involves the former colonising power and the colonised country,' Professor Lee said. 'The government does not think the court could take the historical relationship seriously and it does not know whether the evidence that would be presented to the court would be effective.

'Korea is concerned about an unpredictable outcome and that we could lose this case. If Seoul agreed to go to an international court, it would lose the advantage that it enjoys at the moment by being in control of the islands.

'And if the ruling was not in favour of Korea, no government that had agreed to go through mediation would be able to survive.'

The issue does not worry Mr Kim and his wife. The mountains above their home are wreathed in mist and the sound of the ocean striking the seawall is constant.

They do not miss life on the mainland because Tok-to is the only home they have known for 40 years; they give the impression the only way they will leave is when they are carried off. And that is not likely to happen for the foreseeable future.