These extracts are from The Nautical Magazine and Naval Chronicle for 1866 and give a clear and vivid impression of the seas between Skye and the Western Isles. I have left all spellings as they appeared in the original:
My experience in the navigation of the Minch has been collected in storm and calm, in snow and fog, amidst those difficulties and dangers with which it abounds…
…giving some idea of the weather in that remarkable channel the little Minch; to describe the sudden changes from a quiet calm to a tempestuous raging sea, that will prepare the navigator for what he is to expect there…
…it may be first stated that the Little Minch is the name of a channel or strait in contradistinction to the Great one to the northward of it.
…it will be seen that the Little Minch is a channel from thirteen to twenty-four miles wide, occupying a position between the Isle of Skye and the Hebrides or Western Isles of Scotland, on the West shores of Inverness and Rosshire.
The navigator who has passed through it knows well that it is exposed to the whole fury of the Atlantic Ocean, being entirely open to its southerly gales, and consequently is very seldom in an undisturbed or tranquil state. It is nevertheless the highway of vessels running between the ports of this country and those of Norway, Sweden, Lapland, Prussia, and Russia, carrying timber, tar, tallow, flax, &c. As might be supposed, in so important and extended a trade, vessels of heavy burden, and many smaller ones, frequent its waters in passing to the West coast of Scotland, England, or Ireland.
…the area of water surface which it contains is about 500 square miles: all of which has been minutely sounded, rocks, dangers, and fishing banks carefully searched for, and their places assigned them in the chart.
The greatest depth of water in it is 111 fathoms (666 feet), off Dunvegan Head ; and the least depth at a moderate distance (one mile) from the shores, 18 to 25 fathoms. It does not contain a single known hidden danger, except at its northern extreme, that will be mentioned in its turn.
The Little Minch contains three fishing banks, having depths from 23 to 35 fathoms, the ground composed of sand, shells, and sometimes rock, and perhaps some gravel.
The West side the Minch is very much sheltered from the sea and its westerly gales, by the isles of Harris and North and South Uist, which translated simply means western lands. An entrance from the western sea lies between the two former, named the Sound of Harris. A chart of this sound has been lately compiled by the captain and officers of the Porcupine and Seagull, that gives a good idea of this labyrinth of rocks and shoals, showing the laborious, hazardous, and even dangerous task it must have been to construct. The sound has a good channel, which, with moderate caution, may be used by vessels of any burthen, affording them shelter from the fierce and boisterous Atlantic, and a safe entrance into the comparatively tranquil waters of the Little Minch.
On the western side of the Minch the anchorages are numerous, and much frequented by vessels bound to the southward. Every loch affords a shelter, and the principal are, Lochs Tarbert, Greosavsgh, Stokenisk, and Rodel in the Isle of Harris. Lochs Maddy, Evort, Bahnacaplich, Uskevagh, and Loep, in North Uist; and in South Uist are Lochs Skiport, Ainneart, and Brisdale, with many smaller anchorages for coasters.
We will now ask the reader to turn his attention to the dangers of the navigation and the mode of avoiding them. To the mariner they already have appeared so formidable that he will naturally and anxiously wish to have them at a respectful distance.
The southern entrance to the Minch is quite free from dangers, and the yacht or even the deeply laden barque may fearlessly run into it. But at the north-eastern entrance there are some to be carefully avoided. These are, Sgeir i noe, Sgeir Graitich, Eugenie Rock, (on which a vessel of that name was lately wrecked,) Sgeir na mule, Ghiant South Rock, about 2 1/2 to 3 miles South-westerly of Shiant Isles; this is however, out of the limits of the Little Minch. These are what may be termed hidden dangers, but with the simple yet sufficient directions lately compiled by Captain Otter, of the Porcupine, they may be all easily avoided.
…gales are soon up, and the vessel that is caught in one had better run for snug quarters on their first appearance.
I do not know who the author of this document was, but perhaps those more-familiar with the style of Captain FWL Thomas can suggest whether or not it might have been him?