The Oregon-pine deck was already warm when I emerged from my cabin at dawn. The sea lay becalmed, the anchor slack, the sky cloudless. I dropped over the side and swam the short distance to shore to explore the vast crescent of white sand cradling our anchorage. Anywhere else in the UK such a beach would be overrun. Here on the island of Coll, on the outer fringes of the Inner Hebrides, it was just me and a smattering of insouciant sheep.

The aroma of homemade crumpets and fresh coffee drew me back on board and, under the gaze of a couple of comically watchful seals, we departed, setting a course for Lunga, largest of the uninhabited Treshnish Isles. Along its cliff-edge path, scores of puffins – charmingly indifferent to our presence – fussed around their commandeered burrows, their orange bills stuffed with neat rows of glinting herring.

A few miles east of here is the islet of Staffa, site of Fingal’s Cave. Painted by Turner, with acoustics that inspired Mendelssohn, this is Northern Ireland’s Giant’s Causeway in cubbyhole form – hexagonal basalt columns that retreat nearly 80m into the cliffs. Two centuries ago Wordsworth lamented the plethora of visitors, but our late-afternoon arrival was timed to perfection. As the last tour boat retreated into the distance we swam in the clear waters at the cave’s sun-lit mouth and ventured deep into the cool of this geological cathedral.

Still there was more: a pod of dolphins joined us as we crossed the sparkling waters west of Mull, taking up formation on the bow wave like cetacean outriders. Then, as we dropped anchor in a sheltered lagoon between Ulva and Gometra, first a white-tail sea eagle swooped between the islands and then a brace of stags appeared, perfectly silhouetted high up on the hillside.

Was this a typical day aboard Eda Frandsen, we couldn’t help but wonder? I’m not sure there is such a thing. Some days it’s swimsuits, suncream and millpond calm. Others, hot toddies, oil skins and straining sails. But all are equally compelling. As for a firm schedule, forget about it. ‘Sailing plans,’ our marvellously deadpan skipper, Mungo, warned us on our first day as we departed the little port of Mallaig, ‘are cast in custard’.