Rockall part of the deeply eroded Rockall Igneous Centre that was formed as part of the North Atlantic Igneous Province, approximately 55 million years ago, when the ancient continent of Laurasia was split apart by plate tectonics. Greenland and Europe separated and the northeast Atlantic Ocean was formed between them, eventually leaving Rockall as an isolated islet. The RV "Celtic Explorer" surveyed the Rockall Bank in 2003. The Irish Light Vessel "Granuaile" (the same name as the steamer on the RIA 1896 botany survey) was chartered by the Geological Survey of Ireland, on behalf of the Department of Communications, Marine and
Rockall Ledge, each secured by four 80-tonne rock-anchor bolts. Establishing that the rock is part of the United Kingdom and its development as a light beacon facilitated the incorporation of the island into the District of Harris in the County of Inverness in the Island of Rockall Act 1972 and reinforced the UK Government's position with regard to seabed rights in the area. In 1978, eight members of the Dangerous Sports Club, including David Kirke, one of its founders, held a cocktail party on the island. Former SAS member and survival expert (the Irish born) Tom McClean lived on the island