It is nominally at 28°53′10″S 113°51′35″E / 28.88611°S 113.85972°E / -28.88611; 113.85972,[1] about 4 km (2.5 mi) north and east of Half Moon Reef and is a flat limestone outcrop of about 800 by 420 metres (2,620 by 1,380 ft) in size.
[2] Between June 1727 and March 1728, crew of the Dutch VOC ship Zeewijk were stranded on the island after it struck Half Moon Reef.
Captain Stokes, with Commander John Clements Wickham, named the place Gun Island.
In 1883, Charles Edward Broadhurst, who had been granted a lease for guano export, discovered several campsites, as well as the bones of seals which had evidently been killed for sustenance by the crew of the Zeewijk.
[6] From June to November 1968, a stratigraphic test well was drilled on Gun Island (28º53'30.11"S, 113º51'27.0"E) by BP Petroleum Development Australia.