This stone stands on a mound 1.8m high, and has packing stones visible around its base. The stone itself is (naturally) shaped like a cross with one arm broken off (Crois is Gaelic for cross, Chnoca Breaca is "speckled hill") and is around 2m tall by 40cm wide at the base, and 25cm thick. It is about 90m from the shore.
From The Outer Hebrides and their Legends by Otta F. Swire, 1966:
"It is said that there was a standing stone carved with a cross and known as Crois nan Cnoca Breaca on a small hill on the north boundary of Ormaclett and that it marked the spot where 'Our Saviour of Victory' stood and so long as Howmore Church was in we all those who came to it from the south always knelt there to pray. Martin says that the people bowed to the church from this stone which they set up at the first point from which St. Columba's church at Howmore could be seen and so it was called 'the bowing stone'. One wonders if both the stone and the sacredness of this part of South Uist are not much older than Christianity."