Shetland only has one ferry a day, but it is a roro, and it has flights from four airports in Scotland ( and Kirkwall, and sometimes Bergen).

We were at Kirkwall airport once when flights were being delayed by fog. Announcements for the inter-island flights were made, not by tannoy, but by an airport employee sticking his head out of the office door and talking to us. Kirkwall is my kind of airport. Unfortunately, the next two airports I use will be LHR snd LAX.