UNTIL the discovery of offshore oil, Rockall was destined to remain what it had been for centuries-nothing more than a hazardous curiosity for passing seafarers.

Today it is a prized outpost of sovereignty and periodically becomes the centre of what has been a remarkably restrained and diplomatic dispute between Britain, Ireland, Iceland and Denmark.

The rock is closer to Ireland and geologically-more akin to Iceland or Greenland than continental Europe. But Britain stole a march on rivals by landing a party of marines in 1955 who hoisted a union flag to mark the "formal annexation of Rockall" in the name of Queen Elizabeth II.

Since then there have been: a number of landing's on the 83ft long, 70ft high outcrop, including one in 1969 by the Royal Navy after which the Daily Mail reported: "It is absolutely and undeniably British. The Navy has just invaded it for the third time to make quite sure."

In 1985, Tom McLean, a lone Atlantic sailor, spent 40 days on Rockall for charity, sheltering in a coffin-sized box when the weather got rough.

He warned the campaigners leisure facilities were limited. Long bracing walks are out, as indeed are walks of any description. But you get plenty of fresh sea air and can chat to fishermen on your radio.

"It is completely vertical on one side and rounded and near-vertical on the other," he said. "It's not too dangerous if you go carefully, but if you are not careful you go in," he said.

"In the summer it's OK but in the winter it can be very dangerous and you can get swept off by waves that break right across the top."