Steamers began to ply around the islands in the first part of the 19th century, bringing tourists from Glasgow and beyond. The modern equivalents are the ferries, the lifeline between the islands and the mainland, they transport more or less everything from cars to cows, and from people to ponies
Caledonian MacBrayne — CalMac for short — have the monopoly on almost all the routes, but to me as an outsider they seem a pretty good organization, although recently they have had dreadful problems with ferries breaking down, delayed replacement ferries, and overcrowding in the summer. They are I am told a good employer. It is a characteristic of islanders that they always moan about the ferries, but then their livelihood does depend on them. You need a CalMac timetable to help you plan crew changes, or escapes back to work if you get marooned by bad weather.
CalMac will take you from Oban to Craignure on Mull (and then you need a bus to Tobermory), Coll, Tiree and Lismore. And from Kennacraig on West Loch Tarbert to Islay (either Port Ellen or Port Askaig), and from Tayinloan in Kintyre to Gigha. There is a short ferry, now run by Argyll and Bute Council, from Port Askaig on Islay across the Sound of Islay to Feolin on Jura, but this is in the middle of nowhere and you need the bus to Craighouse. Better, at least for crew changes if you don't need a car, is the passenger-only ferry from Tayvallich to Craighouse and you do have to get yourself to Tayvallich by bus, which is not that easy. And the shortest CalMac ferry ride of all, is across to Kerrera from the mainland. CalMac will also take you across the Sound of Mull from Fishnish to Lochaline, and across Loch Sunart between Tobermory and Kilchoan. And across the Sound of Iona.
There is a wee ferry across the Sound of Mull from Tobermory to Drimnin. But these days more like a water taxi.
There is a small passenger-only ferry between Port Appin and the north end of Lismore, run by Argyll and Bute Council but this is of no great help for crew changes. They also run the very short ferry across to Luing from Seil Island.
Across Loch Linnhe there are two small ferries run by the Lochaber Transport Forum. One between Fort William and Camus nan Gall, and the extraordinarily expensive Corran ferry further south across — not surprisingly — the Corran narrows.
Going further north, the small isles — Rum, Muck, Eigg and Canna — are served by the CalMac ferry from Mallaig. You can also get to Rum, Muck and Eigg from Arisaig on the passenger-only Sheerwater run by Arisaig Marine. And from Mallaig to Armadale on Skye with a CalMac ferry.
Not a ferry, more a small cruise ship, the future of the Waverley is almost always under threat so please donate if you can, to the Paddle Steamer Preservation Society. After all she is the last sea-going paddle steamer in the world, and it is a delight to take a cruise on her. She took her first passengers in 1947. You will often see her in this area although she does cruise around all the British Isles. She stands out a mile because of her elegant shape and broad beam, and she has a very characteristic sound from the triple expansion steam engine (now oil rather than coal-fired).