Boat and Ferry
Because Scotland has so many islands, plus the great Firth of Clyde waterway, ferry services are of paramount importance. Most ferries transport vehicles as well as foot passengers, although a few smaller ones are for passengers only.
It's a good idea to make a reservation ahead of time, although reservations are not absolutely necessary. Most travelers show up on the day of departure and buy their tickets from the stations at the ports. Keep in mind that these are working ferries, not tourist boats. Although journeys are scenic, most people use these ferries as their daily means of public transportation to and from their hometowns.
The main operator is Caledonian MacBrayne, known generally as CalMac. Services extend from the Firth of Clyde in the south, where there's an extensive network, right up to the northwest of Scotland and all the Hebrides. CalMac offers 25 island-hopping itineraries, called Hopscotch, valid for 31 days, which can be combined for tailored exploration. Fares can range from £2 to £6 for a short trip to over £50 for a longer trip with several legs.
The Dunoon–Gourock route on the Clyde is served by Western Ferries (for cars) and Argyll Ferries (for passengers and cycles only).
Northlink Ferries operates a car ferry for Orkney between Scrabster, near Thurso, and Stromness, on the main island of Orkney; and between Aberdeen and Kirkwall, which is also on the mainland of Orkney. Northlink also runs an efficient ferry to Lerwick, Shetland, and Kirkwall, Orkney. The journey to Lerwick is overnight, but comfortable cabins are available. These ferries can be busy in summer, so book well in advance.