Stac Shoaigh (Scottish Gaelic: "stack of Soay") is a sea stack rising 62 metres (203 ft) from the Atlantic Ocean, located between the islands of Hirta and Soay in the St Kilda archipelago in Scotland. It is positioned east of the taller Stac Biorach. Historically Stac Shoaigh was visited by the St Kildans, who collected seabirds and eggs from its cliffs. Stac Shoaigh, along with the rest of the archipelago, is a UNESCO World Heritage Site and is managed by the National Trust for Scotland.
As was the case with Stac Biorach, Stac Shoaigh is uninhabitable but was an important part of St Kilda's subsistence economy because it provided seabirds and their eggs to the inhabitants of St Kilda. During the 18th and 19th centuries, St Kildans visited Stac Shaoigh regularly in search of eggs from gannets and fulmars, which were carried back to Hirta in woven grass baskets. This was a risky process because it was often undertaken using ropes and homemade climbing equipment. Harvesting on stacks in St. Kilda was last undertaken in the mid-19th century but was abandoned due to a decline in population and changes in economic circumstances.
Sir Robert Moray visited St. Kilda in the latter half of the 17th century and gave a vivid account of the islanders' sea stack climbs in his paper to the Royal Society. He wrote of the ascent of the sea-stacks from a long-boat:<blockquote>"After they landed, a man having room for but one of his feet, he must climb up 12 or 16 fathoms high. Then he comes to a place where having but room for his left foot and left hand, he must leap from thence to another place before him, which if he hit right the rest of the ascent is easy... but if he misseth that foot-step (as often times they do) he falls into the sea and the (boat's) company takes him in and he sits still until he is a little refreshed and then he tries it again, for everyone there is not able for that sport."</blockquote>
Martin Martin visited St Kilda in 1697 and provided a vivid description of this place he named "Stack-donn" (meaning "mischievous rock"): <blockquote>"It is much of the form and height of a steeple; there is a very great dexterity, and it is reckoned no small gallantry to climb this rock, especially that part of it called the Thumb, which is so little, that of all the parts of a man's body, the thumb only can lay hold on it... and having a rope about his middle, that he casts down to the boat, by the help of which he carries up as many persons as are designed for fowling at this time; the foreman, or principal climber, has the reward of four fowls bestowed upon him above his proportion; and, perhaps, one might think four thousand too little to compensate so great a danger as this man incurs; he has this advantage by it, that he is recorded among their greatest heroes; as are all the foremen who lead the van in getting up this mischievous rock."</blockquote>
The climbing ability of young men from St. Kilda was tested by scaling sea stacks like Stac Shoaigh. In the past, if an individual could not climb the sea stacks, he was not allowed to marry.
Before any climbing could be undertaken, a safe landing from the boat had to be accomplished, and this was frequently the most hazardous part of an expedition to a stack like Stac Shoaigh. The boatmen had to operate in the heavy Atlantic swell, taking the vessel up and down the rock face even in good weather. The leader of the expedition, referred to as the "officer" or "gingach," had to be the first to land and the last to leave. According to one account, the author notes:<blockquote>"The Men seldom grow old; and seldom was it ever known, that any man died in his Bed there, but was either drowned or broke his neck."</blockquote>
The first recorded case of recreational sea stack climbing in Scotland was carried out by Richard Manliffe Barrington in 1883 on Stac Biorach. This was described as the most dangerous climb he had ever undertaken by an experienced alpinist. However, he was assisted in this endeavor by two islanders from Hirta, Donald McDonald and Donald McQueen.
Currently, all climbing in the St. Kilda archipelago is subject to permission from the National Trust for Scotland, who rarely grant permission. A small team of climbers from Britain including Robbie Phillips of Edinburgh, successfully climbed Stac Biorach for the first time in over 130 years in 2023. Phillips reflected:<blockquote>"It was like walking in the footsteps, or climbing in the fingerprints, of the St Kildans. It's a testament to their bravery and mental fortitude; to climb onto that sea stack 70 m above the raging Atlantic without even shoes is wild to imagine.</blockquote>
Like all the other stacks and islands in the archipelago of St Kilda, the island of Stac Shoaigh is part of an ecosystem that is exceptionally rich in bird life. The archipelago is home to vast breeding colonies of seabirds such as the Atlantic gannet, the common guillemot, the Atlantic puffin, the northern fulmar and the razorbill.
Currently, the St Kilda group is a national nature reserve, and the seabirds are protected. The location of the St Kilda group and the cliffs of some of the stacks, such as Stac Shoaigh, make landing difficult, and this may have been a contributory factor to the safety and exploitation of the seabirds in earlier times.
In the past, birds and their eggs played an important part in the lives of the islanders. Eyewitness accounts describe guillemot eggs as being "very good eating when fresh ... After they are incubated for a few days most of the egg appears ... and in this condition they are also relished." However, in recent years, the population of seabirds in St. Kilda has faced alarming declines. For example, in 2023, a survey found that the population of fulmars, guillemots, razorbills, and kittiwakes had declined by over 35% since 1999.
The stack is included in the promoted protection regime of the Seas off St Kilda SPA and the larger-scale archipelago-scale SPA designations.
For visitors, Stac Shoaigh can be seen from a boat trip to Village Bay on Hirta, the main landing destination for the islands. According to NTS, visitors can only access the island by boat, using approved tender landings, and it is rarely possible for people to undertake a holiday or a climb from the sea stacks without special permission.