In Carlingford Lough, Ireland, last autumn, when there was but a fine-weather breeze blowing outside, the puffs off the mountain on the south of the lough took the form of a succession of regular waterspouts, any one of which would have twisted the mast out of the boat or capsized her if it had struck her. We kept as far to leeward as we could, and most of them died away before they crossed our track, but they felt very uncanny.
Speaking generally, high land is always dangerous for boat-sailing, as well as trying to the temper. On a day when there is nothing but a fine-weather breeze elsewhere, under high land you are liable to get puffs as violent while they last as a gale of wind. It is as though the hills bottled up and concentrated the wind, so that when it is let loose it comes with double force; and these puffs are specially dangerous to a boat apart from their force: first, because the angle at which they will strike is so uncertain, and secondly, because, coming from above and striking downwards, a boat does not relieve the pressure on her sails by heeling over as she does when the wind blows horizontally along the water. This is the reason why you will probably find that the squalls that go nearest capsizing your boat are not those that you have seen tearing towards you turning the water into smoke as they come, violent as these may be, but those which you have hardly seen a sign of on the water at all, and which strike the sails with a downward blow straight from the mountain side. The Sound of Raasay, outside Portree Harbour, when a westerly wind is blowing over the tremendous cliffs of Skye, is a fine place for the study of these phenomena.
When the wind is blowing up or down a channel with high land on either hand, the fiercest puffs will be near the sides which seem to concentrate the wind, and the safest place will be the middle of the channel. One day, in Loch Scavaig, beating out of that inferno of furious winds against the usual succession of tearing puffs, with double-reefed sails and all passengers down in the bottom of the boat, I stood rather far over one tack under the high mountain on the west side. Just as I was preparing to go about a furious blast struck the boat like a cannon-shot. I thrust the helm down, letting fly the mainsheet. The foresheet fortunately carried away of itself, but for a few seconds a volume of water poured over the rail, and I thought we should go over or fill. A minute later, as we were standing off on the other tack, setting things to rights and pruning our ruffled plumes, my coxswain, a most excellent boat-sailer but a man of a somewhat sardonic humour, remarked grimly, 'I should think that would be a lesson to you in future not to stand over too far under high land.' It has been.