These were beamy, deep draughted vessels designed for the carriage of cargoes rather than speed, around 60-80 feet long and with one or two masts. Some ran to a schedule, e.g. the mail smacks which ran from Poolewe to Stornoway until a steam service to Ullapool was introduced in the 1840s and from Dunvegan to Lochmaddy and Lochboisdale (N and S Uist) until the 1880s. But most just sailed as and when a cargo offered. Passenger accommodation was rudimentary in the extreme.
It's pointless trying to describe such a vessel without a picture but when I started to write this, I couldn't think of any picture of a West Highland sailing smack I'd ever seen except the one - called the Mary Stewart - only the vestigial remains of which are sunk in the sand at Scarinish on the island of Tiree.
Picture credit James and Tizzy
But in the course of googling a picture of the remains of the Mary Stewart, I came across a fantastic series of pictures of smacks at Scarinish taken by Erskine Beveridge (1851-1920). He was a Dunfermline textile manufacturer and amateur antiquarian who took numerous photographs in the Highlands and Islands of Scotland. I believe the following photos date from about the 1870s:-
It seems that Tiree was quite a centre for sailing smacks trading around the islands but I don't know if any of these ships is the Mary Stewart. The building in the background is the Scarinish Hotel which is still very much on the go and getting some good reviews on Tripadvisor.
You can see more of Erskine Beveridge's pictures on the website of the Royal Commission on Ancient and Historical Monuments website. Just type "Erskine Beveridge" in as the search term and check the "online items only" box to get only returns with photos.
The sailing smacks were gradually replaced in the 1880s by the steamers of David MacBrayne, Martin Orme and John MacCallum for the carriage of passengers, livestock and cargo and the "puffer" for the carriage of bulk loads (typically coal). So I leave this post with a nice J Arthur Dixon postcard from the 1960s showing two puffers at Scarinish just yards from the remains of the Mary Stewart.