The suburb is located on the bay itself, but the locality boundaries stretch as far west as Point Nepean and incorporate a section of Bass Strait coastline.

The historic reserve became famous when Prime Minister of Australia Harold Holt disappeared while swimming inside the facility at Cheviot Beach on 17 December 1967 and was officially presumed dead two days later, although a formal inquest into his death did not take place until 2005.

The Portsea Pier is the home to the spectacular weedy sea dragon, as well as many other fish species, including numerous pufferfish.

Corsair Rock, just at the entrance to Port Philip, is a well-known surf spot to locals and professional surfers.

[5] The annual Portsea Polo event is held at Jarman Oval, near the former quarantine station on Point Nepean.

[8] The Australian Crawl song "Hoochie Gucci Fiorucci Mama" (from the 1980 album The Boys Light Up) was written about Portsea.