The water turns emerald and purple-blue, there are detonations of yellow and scarlet on the hillsides, and small white houses with luridly painted, corrugated-iron roofs appear from the shadows. All of this is a trick, a surprise, because until you were just about to leave - it was raining.
Other parts of Britain may face hosepipe bans and parched river beds as a result of global climate change, but Wester Ross, like most of the rest of the Western Scottish Highlands, will be forever damp. While London sweltered its way through the Easter break, we were squelching in welly boots, bent double in waterproofs, through raw wind and horizontal rain.
And it was wonderful. Wester Ross is not for sun-worshippers or easily bored urban Channel-hoppers. Its awesome mountains and extraordinary vistas, which make all those Victorian engravers and School-of-Landseer painters look like photo-realists, are well protected from the rest of Britain - by distance, most obviously, but also by climate. In winter, the days are short. The wind rarely dies. Colour sinks and disappears. Summers can produce sudden hot spells, but also bring the midges. Spring and autumn are the best times, but they are not ... well, predictably good.
And all this is a blessing, if well disguised in sheets of rain: many years ago I remember hearing from a German tourist on a fine Wester Ross beach, with sun beating down on the flour-white sand, that once people at home heard about it, this Scottish coast would be ''covered with hotels, like Spain''.
They were never built: too rainy for mass tourism. So those people who do come, taking the train and bus, or flying to Inverness and driving, rent cottages or stay in bed-and-breakfast places.
Once, not so long ago, Highland guest houses tended to be pretty poor: nylon sheets, fried eggs and beans for breakfast, a pervasive smell of cigarettes in the lounge. Today, though, there is a little flowering of genuinely good small hotels and guest houses. This is important: you need warm and comforting rooms, and excellent food, to recover from a cold day on the hills, or from fishing. We found, in a corner of Wester Ross we know well, a croft house offering sumptuous breakfasts - local kippers, duck eggs, griddle scones - roaring open fires, and excellent dinners, including venison, trout, wonderful Scottish cheeses and a boggling sequence of puddings.
It was a good Scottish welcome, though Mairi and Roger Beeson are typical of many modern Highlanders: they met in a London advertising agency and moved north only recently. Their Obinan Croft (''the last house by the shore'') is near Mellon Udrigle beach and looks out at a vast sweep of sea, the Summer Isles and the Sutherland mountains. We left after four nights, well blown about and rain-washed, but also seriously distended. For those prepared to take a short flight from London, and fed up with France, it's worth looking north.
Roger and Mairi Beeson can be contacted at Obinan Croft, Laide, Achnasheen, Wester Ross 1V22 2NU (01445731548).