The inlet is a large shallow estuary at the eastern end of the d'Entrecasteaux National Park, linked to the Southern Ocean by a narrow seasonally open channel situated between two high sand dune systems.

[2] The inlet is the only large estuary left in the South West that has not been significantly altered by development within its catchment area or along its shores.

The salinity varies greatly depending on river discharge, the season and whether the bar is open or not.

Broke Inlet is listed as a regionally significant wetland with Environment Australia.

[4] The inlet's and locality's names are thought to be based on Philip Broke, captain of HMS Shannon, a frigate of the Royal Navy, best known for its victory over USS Chesapeake in 1813.