This island is approximately 115 km south of Bird Islet, part of the east end of Wreck Reefs
The island is a mound of coral debris and grit 5.8m high covered in grass and creepers up to 1m high . An automatic weather station, with two radio masts and a silver-painted hut, stands on the north-east end of the island. The island is almost entirely surrounded by reefs: there are three narrow boat passages through the reefs on the northern side. The best entrance is the center one, located 350 meters north of the eastern end of Cato Island; it has a conspicuous rock at half tide on its Eastern side
The island lies on the western end of an oval-shaped reef enclosing a lagoon. The lagoon contains numerous coral heads. The sea breaks over the reef in all weathers. The reef lies on Cato Bank, which falls away steeply on all sides.
Hutchison Rock 23°15′S 155°36′E, with a depth of 5.5m, lies 3.5 km East of Cato Reef.
Danger Patch lies near the outer end of the Eastern ledge of Cato Bank. A tidal race is found between the Eastern end of Cato Reef and Danger Patch
