IT goes without saying that ferries are important to the future of our islands. But it must be said that a rise in costs of more than £100 million in a year will make everyone concerned with the islands’ welfare pause for thought.

In a sense, it is not even the amount as the lack of clarity about how it is spent that causes concern. That concern deepens when public finance watchdog Audit Scotland identifies a lack of long-term strategy for future spending. To take one example. Transport Scotland pays £155m a year in harbour fees and yet it has no record of which improvements are funded nor of conditions in the harbours it uses.

Again, substantial investment could be required. Who knows? Audit Scotland has concerns about the annual fee paid to Lloyds Bank under a lease-back arrangement for the Stornoway-Ullapool ferry. What happens when that contract ends in 2022 is anybody’s guess.

With weaknesses identified in procurement arrangements for the Clyde and Hebrides contract, why does Caledonian MacBrayne being the only compliant tenderer mean no system is seemingly necessary to examine its 350 commitments?

Ferries are not cheap. Some costs are known: new routes, new ships, cheaper fares through Road Equivalent Tariff; all justifiable. But we need to know the full picture and that there is a strategy in place for future spending.