Port Phillip Ferries has emerged as a potential operator of a Yarra River ferry service to take passengers from South Yarra and Richmond to the CBD and Docklands.

The privately owned ferry service - which currently runs between Portarlington, on the Bellarine Peninsula, and Docklands - has confirmed it is discussing a river commuter service with Richmond's $1 billion Nylex site developer Caydon Property Group.

Caydon first raised the river commuter service in Domain as a travel alternative to the congestion on Punt Road and Alexandra Avenue.

The developer said the proposed ferry would take about seven minutes to travel from Cremorne to the city. It suggested other stops could include the Richmond sporting precinct and around Chapel Street in South Yarra.