Greens have said they want to work with ferry bosses at Calmac to set up new links between Scotland and Europe.
The party believes publicly owned services could run from places such as Rosyth, which has previously had ferry links with Europe.
Green co-leader Lorna Slater said tailbacks linked to Brexit had shown there was a need for more ways of getting to the continent.
And she added that having “new low-carbon ferries carrying freight and holidaymakers” would also help tackle climate change.
Greens believe that new ferry routes could be a popular alternative to flights to Europe.
Ms Slater said: “Scotland’s journey back to Europe starts at this election, and the Scottish Greens want to see new links established from places like Rosyth, which has the advantage of already having infrastructure in place.”
She added: “This is a significant strategic investment for Scotland. Brexit has shown we need more links to Europe, with tailbacks at English ports.
“And we have a publicly owned operator ready to step up to give Scots more opportunities to get to Europe without having to fly.
“I see Scotland being at the forefront of Europe’s plans to tackle the climate emergency, and new low-carbon ferries carrying freight and holidaymakers to the continent would be a great start.”