Plans for the UK's first National Marine Park are being developed.
The proposals for Plymouth Sound would establish a "world leading demonstration centre for marine technologies" and "strengthen marine conservation", the city council said.
The authority has announced it will lead the project.
It said cash from the Marine Management Organisation would help get the scheme under way and a public consultation has been launched.
Councillor Sue Dann said Plymouth was "ideally placed to be the UK's first National Marine Park".
Matt Frost from the Marine Biological Association, said: "We believe the benefits will include raising the profile of our marine environment nationally, including the need for world-class science to understand and protect it, and boosting the local economy that depends on it."
Roger Maslin, CEO of Plymouth's National Marine Aquarium, said it hoped to help "inspire and empower the community to understand, enjoy, value and care for our ocean" through the new plans, and hoped it will "encourage the creation of a network of marine parks around the UK".