The harbour and surrounding land has been designated as an Area of Outstanding Natural Beauty (AONB) and a biological and geological Site of Special Scientific Interest (SSSI).

Its wide expanses and intricate creeks are at the same time a major wildlife haven and among some of Britain's most popular boating waters.

More than 7,500 Brent geese overwinter on the intertidal mud-land and adjacent farmland and around 55,000 birds reside in or visit the Harbour throughout the year.

[citation needed] The western boundary with Langstone Harbour is defined by a historic causeway known as the wade way, once the principal access from Hayling Island to the mainland, but since bisected by a deep channel for the Portsmouth and Chichester Canal in the 1820s, and no longer safely traversable.

[citation needed] The harbour has diverse habitats, including intertidal mudflats, shingle, saltmarsh, sand dunes, marshes and woodland.

[15] The quality of water in the harbour was called into question when samples taken in 2022 were found to contain traces of numerous chemical compounds including prescribed medicines.

During the summer regular trips depart from Emsworth on Solar Heritage and on the Victorian oyster boat Terror.

There is a network of footpaths for walkers and a cycle route from Chichester to West Wittering which passes through harbour countryside.