Ailsa Craig (Gaelic: Creag Ealasaid) is an uninhabited island in the Firth of Clyde, 9 miles off the coast of Ayrshire. It measures about 3⁄4 of a mile north-south by ½ a mile east-west, and rises abruptly to 1120 ft / 340 m. Its distinctive pyramid can be seen from afar in good weather. It's nowadays a birdlife reserve, though its granite is still quarried to make curling stones.
Ailsa Craig is a pluton, a volcanic upwelling from about 60 million years ago, along with similar hills on the nearby island of Arran. Typically a pluton has no erupting volcano, but magma wells up and shoulders aside pre-existing rock. It then cools very slowly into coarse-grained granite that is hard-wearing, so it persists long after surrounding features have eroded away. Plutons have formed throughout Earth's existence and this one arose in the Palaeogene, formerly called the Early Tertiary. In that period the continents came close to their present positions, the global climate cooled, and dinosaurs suffered mass extinction to be replaced by mammals. Then followed the ice ages, which scraped and polished the surface of Ailsa Craig, and transported boulders from it as far away as Pembroke and Donegal. Any Stone Age person stranded amid the frozen wastes would be sure to think: "Hey, what a colossal ice rink and helluva curling stone".
The island has fresh water but almost no topsoil, and it's a long way to bring sheep for grazing, so only intermittently was it inhabited. Around 1400 it was owned by the Cluniac monks of Crossraguel, and has been a bolthole for fugitives and landing-beach for fishermen and pirates. It's always been a nesting place for seabirds and stop-off for migratory flocks: the solan geese were hunted into modern times. Yet this remote spot once had a gasworks and two railways.
From the mid-19th century Ailsa Craig was quarried for its distinctive granite "Ailsite", a form of riebeckite (formula Na<sub>2</sub>(Fe<sup>2+</sup><sub>3</sub>Fe<sup>3+</sup><sub>2</sub>)Si<sub>8</sub>O<sub>22</sub>(OH)<sub>2</sub>, since you were wondering). The floor of the Chapel of the Thistle in St Giles Cathedral Edinburgh is an example of Ailsite granite. The railways - really just wagon haulways - were built then, and the visiting freighters brought rats, which set about the island bird population. A lighthouse was built by the Stevensons in 1886, and automated in 1990, when its keepers the last island residents left. Ailsa Craig has no safe all-weather harbour and the quarry was unprofitable for mass extraction of building stone, but found a niche use as a source of curling stones. Curling is the sport of sliding stone bowls over ice towards a target area, and the curl is induced by the spin of the bowl as it travels, offset by brushing the ice to speed and straighten its path. Curling emerged in the 16th century in Scotland and the Netherlands - it's not agreed which was first, but both had freezing cold winters and strong trading links. Initially any hefty flat-based stone would serve, then the sport was regularised and a handle became standard. Ailsa Craig is the traditional source, fashioned into stones by Kays in Mauchline near Ayr. Trefor quarry on the Llŷn Peninsula in Wales exports stone to the Canada Curling Company. The stone has a concave base, so all the contact with the ice is on its rim. The ice is not flat but "pebbled" by frozen droplets of water for a faster running surface. This means that the contact is highly concentrated, so a completely impervious stone is necessary - otherwise water would be forced in at microscopic level, would then freeze and crack the structure, and the stone would soon become pitted and unusable. Kays only quarry once every few years, taking 2000 ton batches of three Ailsite varieties (green, blue, and a little bit of red) back to the mainland for storage until required for manufacture. These amounts aren't going to diminish the island any time soon.
The island is now a bird sanctuary managed by the Royal Society for the Protection of Birds (RSPB). In 1991 the rats were eradicated by poison: they had been especially damaging to puffins, which nest in easily accessible burrows, where eggs and chicks are unguarded while the adults fish. The rabbits are also an introduced species but are much less damaging and their presence is tolerated. Puffins soon re-colonised the island, and all species showed a rebound in numbers.
There are no scheduled ferries, and most visitors get here on a boat trip. Most trips are non-landing, circumnavigating to view the wildlife. Ailsa Craig is also within sea-kayaking range, but you're nine miles out, think about the changing conditions and the getting back.
Girvan is the usual point of departure for trips, see that page for details. McCrindle the main boat operator advertises year-round sailings - in reality the weather and lack of customers make trips unlikely in winter.
Cruises of the west coast and Hebrides sometimes approach Ailsa Craig. One example is the Waverley, the world's last sea-going paddle steamer, which ranges around the Firth of Clyde in summer. This elderly vessel has had long spells hospitalised for repair, and it's a wonder she keeps going.
The landing jetty on Ailsa Craig is on the sheltered east side, just north of the lighthouse.
Walk everywhere. You need stout boots.
Wildlife spotting: the skies are especially full of sea birds during the nesting season of spring and early summer.
Bring everything you need with you, as there is no food or drink on the island.
There is no accommodation on the island, and camping is not permitted.
Boat trips are generally open or only partly covered, so you need warm, windproof and waterproof clothing, at any time of year.
The cliffs are dangerous and the ground nearby is often slippery from drizzle and bird-poo.
As of Oct 2022, the island has no mobile signal. Consider leaving your phone somewhere safe ashore, rather than risk a soaking or breakage in a stumble.
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