Multi-million pound investment plans have been drawn up for Ardrossan Harbour in an effort to retain a lifeline ferry service to Arran.
North Ayrshire Council and harbour owner Peel Ports said they aimed to save the "shortest, fastest and cheapest" route to Brodick.
The existing link has come under threat from Associated British Ports (ABP).
ABP is bidding for the service to be switched from Ardrossan to its port at Troon in South Ayrshire.
The new proposals for Ardrossan involve Peel Ports investing in "significant infrastructure upgrades" at the site - including improvements to harbour walls, bollards, gantries, fenders and signage.
In turn, North Ayrshire Council would make improvements to the passenger terminal, roads, car park and connectivity with the town centre.
The council and Peel Ports said the "suite of integrated proposals" would significantly improve passenger and berthing facilities at Ardrossan for the new generation of ferries being introduced by Calmac in 2018.
They will sound out key stakeholders over the next few weeks before presenting the proposals to Transport Minister Humza Yousaf before Christmas.
Doug Coleman, from Peel Ports, said: "We're committed to a multi-million pound investment in the marine infrastructure at Ardrossan to improve connections with Arran via the shortest, fastest and cheapest route.
"These will be bespoke facilities and modern infrastructure specifically designed for the new £48.5m ferry, which will itself dramatically improve docking reliability in poor weather."
ABP has already announced plans to invest £8m on a new passenger ferry terminal at Troon if it picks up the Arran service.
Proposals put forward to the Scottish government include a new Arran Community Fund, which will generate £50,000 a year for good causes.
ABP has claimed that the existing service from Ardrossan is "dogged by weather conditions that frequently exceed the capabilities of the port and result in a significant level of service cancellations".
It also claims that the Port of Troon is already well equipped to handle the next generation of Calmac ferries.