Fares are to rise on some ferry routes following a review of a subsidy scheme.
A cap of 10.6% has been placed on services linking the mainland with the Western Isles, Coll and Tiree from next year.
The change, which will also affect Islay, Colonsay and Gigha, updates the road-equivalent tariff (RET), which links fares to the cost of travelling an equivalent distance on land. The average increase will be 8.2% for passenger, car and small commercial vehicle fares.
It is among a number of announcements in the Scottish Government's ferries plan, which also commits to new services and road improvements.
A passenger and car ferry will be tested in summer between Campbeltown and Ayrshire via Arran, and improvements are planned for services linking Oban, Coll, Tiree, the Small Isles, Mull and Cumbrae, among others. An upgrade to the A83 between Campbeltown and Kennacraig will be considered.
Despite the focus on ferries, a weekend air service is also to be tried out between the Mull of Kintyre and Glasgow over the next two summers.
Transport minister Keith Brown said: "The long-term future of ferry services in Scotland is vital not only for Scotland's economic wellbeing but also for the people in our island and remote communities. Having concluded an extensive consultation which saw over 2,000 responses, today we are laying out how we will expand and improve ferry services across Scotland.
"Despite the substantial financial pressures placed on us by Westminster, we are determined to make good on our promise to deliver improved ferry services on a progressive basis and the final ferries plan will be our cornerstone in doing just that."
The plan identifies 15 new vessels to come into service between now and 2025, worth £295 million, he said. Port and harbour works worth £73 million have also been identified over the same period.
On the RET changes, he said the update reflects the current costs of driving a car. He said: "The additional revenue generated by applying the updated RET formula for passengers, cars and small commercial vehicles will be reinvested in commercial vehicle fares, in order to reduce the impact of the removal of RET for commercial vehicles on services to the Western Isles, Coll and Tiree."