The lagoon connects to Wide Firth through a shingle bar at mid-tide level, via a narrow channel about 3m wide and 10m long.The lagoon is 0.3 km long, about 100 m wide, with a maximum depth of 0.4 m . The tidal range is less than 0.3m but the majority of the lagoon drains at low water to expose mudflats.

There is a very little disturbance from wave action or tidal currents.The lagoon is surrounded by grassland.The main basin of the lagoon, between 0.1 m height and 0.1m depth, consisted of soft anoxic mud. Most of the basin drains at low tide level. This habitat was dominated by a mat of the green algae Enteromorpha intestinalis and Enteromorpha prolifera.The entrance of channel consisted of pebbles and cobbles which lie between 0 and 0.4 m depth.