Stone shelter sited on western side of small bay or inlet, referred to as the 'bouy-keeper's cottage' by Douglas Hague when photographed by him in 1971. The shelter, largely dry-stone built but mortared in places, comprises four walls built mostly of quarry stone but with a small proportion of beach cobbles. Its west wall is built against a rock outcrop; the structure is otherwise a rectangle which narrows slightly from north to south.

The building measures 4.6m north-south, with a 3.5m long south wall and a longer 3.8m long north wall. A simple doorway is sited in the north wall, measuring 0.9m wide. The walls are 0.6m thick and stand with a maximum external height of 1.6m, and an internal height of 1.7m. Since being photographed by Hague in 1971 the north-east angle of the building has partly collapsed, but is otherwise largely an intact ruin. There is a small recess in the rear (west) wall.

This structure sites at the southern end of a longer earthwork platform, which may have originally held a building. The stone from the former structure may have been robbed to build this buoy-keepers cottage.

A low mooring post, consisting of a 25cm-high orthostat, can be seen some 15m north-east of the ruin.

Visited by T. Driver, RCAHMW, 19 April 2016