The government has earmarked £77 million to develop green and zero-emission maritime transport.
Cargo ships, ferries and cruise ships will all set sail within two years thanks to the funding, the government claims.
Successful innovators and businesses must show they can work with ports and operators to have a zero-emission boat on British waters by 2025 at the latest to secure the investment.
Electric vessels, hydrogen, ammonia and wind-assisted ships are the focus of the project.
The Zero Emission Vessels and Infrastructure (ZEVI) competition will be overseen by Innovate UK.
Transport Secretary Mark Harper said: “This multi-million-pound investment will help the latest tech ideas become reality and ensure UK waters will play host to green cargo ships, ferries and cruises in the next few years.
“Our funding will support a cleaner freight system, a more environmentally friendly tourism industry and a net zero maritime sector.”
“Innovate UK will work closely with the Department for Transport in delivering the ZEVI competition, resulting in multi-year real world demonstrations of clean maritime technologies around the UK,” added Mike Biddle, Executive Director for Net Zero at Innovate UK.