Cockrone Lagoon is the most southern of the four coastal lagoons in Gosford. The lagoon has a surface area of approximately 0.38 km2 and a catchment area of 7.2 km2.
The vast majority of the catchment is underdeveloped rural land, predominantly forest with farms on the lower slopes. On the north east side of the lagoon lies part of the suburb of Copacabana, whilst about half of the suburb of MacMasters Beach lies within the south east part of the catchment. Beyond MacMasters Beach the catchment adjoins Bouddi National Park, separated by The Scenic Drive.
The bed level of the lagoon appears to slope fairly uniformly form the west/northwest shores down to –0.1 m AHD (Australian Height Datum) near the beach berm, and the water levels inside the lagoon are not usually influenced by the ocean tides.