The South Sutor 4-inch Q.F. Battery is sometimes referred to as the Number 3 Battery and lies to the West of the main battery site with the other two batteries. The South Sutor 5-inch battery was planned in 1913 and built that year under Admiralty control. Similar to Ascension Island a Wei Hai Wei, the coastal defences at Cromarty were a naval responsibility with Royal Marine Artillery.
The Battery remained in use until at least the end of World War I, but was not active in 1939. It was intended to cover the minefield and boom defences and deal with Motor Torpedo Boats and lighter vessels. There were four similar 4-inch guns at North Cromarty Battery on the opposite headland.
For more information on the 4-inch Q.F. gun see here.
The Battery is now slowly disappearing. The gun emplacements are on a ledge cut out of the hillsides. Soil and vegetation now covers the two emplacements, and trees have also fallen over the area. The underground magazine corridor with office and single magazine remains in good condition, although sometimes flooded. The slope above the battery is very steep, although the old zig zag path can still be used in parts. Little more remains that a footprint in respect of the two Defence Electric Lights. Foliage, trees and earth are slowly burying what remains.