It is about three miles in circuit, with deep water in the centre: the edge is covered, but some straggling rocky lumps show at intervals above the surface of the water.

The east side of the reef extends about North-North-East and South-South-West for one mile, but the greatest extent seemed to be West-North-West and East-South-East.
MIDDLETON'S SHOAL is in latitude 29 degrees 14 minutes, and longitude 158 degrees 53 minutes.

(See Horsburgh volume 2 page 508.) CATO'S BANK is in latitude 23 degrees 6 minutes, and longitude 155 degrees 23 minutes.

(Flinders volume 2 page 298 and Horsburgh volume 2 page 509.) WRECK REEF is in latitude 22 degrees 11 minutes 23 seconds, and longitude 155 degrees 18 minutes 50 seconds.

(Flinders volume 2 page 330 and Horsburgh volume 2 page 509.) CARNS, or MID-DAY REEF, was discovered by Mr.Carns, the master of the ship Neptune, on the 21st of June, 1818, having taken a departure the day before from Sandy Cape.