Maritime UK has criticised the government's new Transport Decarbonisation Plan for overlooking shipping.
The industry body for the £46bn ($64bn) domestic maritime sector slammed the blueprint for net-zero emissions transport by 2050 as "a disappointment that is full of rhetoric rather than real investment".
Maritime UK said shipping has been largely ignored, despite the industry being larger than aviation and rail combined.
The plan recognises that power points for vessels need to be installed around the UK coast.
But Ben Murray, chief executive of Maritime UK, said: "There is no reason to delay getting on and installing them."
No money coming
He added: "No headline commitments and no money to get on with the task in front of us. We know how other countries have got there and that is through co-investment by industry and government."
Murray said the country has the capability to identify the solutions to propel net-zero vessels.
"If we are to level up our coastal communities and bring shipbuilding home, we need government to do what other maritime nations do, and invest in research and innovation on a scale similar to UK automotive and aviation," he argued.
Spending review needed
Murray called for a spending review in the autumn to provide the investment to make the commitments real.
State broadcaster the BBC summed up the message of the plan as "you can carry on flying".
Ministers have said new technology will allow domestic flights to be almost emissions-free by 2040, and international aviation to be near zero-carbon by mid-century.
But this policy has been dismissed by environmentalists, who say the government is putting too much faith in innovation.
Transport is responsible for 27% of the UK's emissions. This makes it the single biggest emitting sector.