As it first appeared in the gloaming of a glorious late summer evening, it looked as if a periscope was heading towards us, leaving a V-shaped wake.
Gradually the neck and beak of a swan became more obvious. Soon afterwards it was joined by its partner.
With drinks being sipped on the deck of the Glen Massan after the last of a sequence of sumptuous dinners, the serenity of the scene was complete.
There can be few places on Earth more beautiful than the setting we were in, anchored a couple of hundred yards off Mull on the stillest of evenings. The arrival of this elegant pair, who apparently always stop by when the boat visits this part of the coastline, aware that some of the tastiest titbits imaginable are likely to be heading their way, contributed to a near perfect end to a quite lovely week.
It had not seemed likely to be that way when a few of our number had been queasily eyeing one another as we made our initial passage out of Oban harbour six days earlier in rather choppy water.
Even then, though, the tone had been set when we had embarked to be met by head chef Andie or, as she claimed to prefer to be called, "Cookie", who had the bubbly open and ready to be passed around as soon as the tender had brought us to our home for the week.
She may be part of a team of four but the success of the voyage was entirely dependent on the miracles this woman performs in a galley that is around three feet wide by eight feet long in not only catering for 10 guests and her fellow crewmen, but doing so at a level that is comparable with some of the country's finest restaurants.
Days begin with breakfast banquets that feature porridge soused in honey and malt whisky and a different hot dish each morning; elevenses comprise sweet and sticky biscuits and pastries; lunch-time soups and souffles generate the sense of soporific satisfaction that forced the Spanish to introduce the siesta; cakes and biscuits accompany afternoon tea; and delicacies dominate the dinner menu, from seared scallops to sizzling steaks, lobster tails to lamb shanks, caviar to crab claws, raspberry sorbet to rhubarb crumble and cheesecake to chocolate mousse.
With plentiful wine and measures of port to accompany a stunning array of cheeses that varied every night, it is little wonder that Andie, only half-jokingly, cites her target as an average weight increase of 5kg per passenger by the end of each cruise.
Ironic, then, that we perhaps saw Andie at her very best when events conspired to prevent her from cooking for us.
Perhaps it was down to bad karma. There had been something rather morbidly fascinating about the visit to what is apparently known locally as Dead Island on an expedition led by first mate Mark, but perhaps, on the little outcrop in the bay off Carnoch that has been turned into a cemetery, someone walked over the wrong grave.
It was certainly a strange little excursion, the overgrown land strewn with graves dating back to the mid-19th century while the lintel from the burnt-out home of MacIain forms part of the island's most imposing stone-built memorial, a tribute to the chieftain of the clan that suffered the Massacre of Glencoe.
The message scrawled on the back of one gravestone could hardly have been more sinisterly portentous: "My cup has run, Your cup is running, Be wise with time, Your time is coming."
Whether our progress was cursed or not, the following morning the engines failed meaning not only that we were not going anywhere, but that there was no power to fuel Andie's galley.
Horrified at the prospect that we might spend a single moment not stuffed to the gunnels, she swung into action, racing over to the mainland to arrange breakfast and a guided coach trip up through the glen to Kinlochleven, while she was ensuring that we did not go without lunch as she set about organising dinner at The Gathering which entertained us royally that evening.
I relay all of this culinary detail by way of stressing that it is hard to imagine ever receiving more attentive hospitality than on a Majestic Line cruise. There is certainly every danger of achieving that target weight gain because all the food, which is of the highest quality and, where possible, locally sourced - right down to Mark nipping off on the tender to pick up netfuls of mussels direct from an off-shore mussel farm - as well as all drinks with dinner are included in the price.
However, the cuisine alone could not be what draws people to spend a week at a time on a boat that includes Neil Munro's wondrous Para Handy Tales in its library and, in its way, has just a hint of The Vital Spark about it with jovial skipper Jimmy Campbell leading a crew of four while engineer Ray does battle with his engines.
Their mission is to show off Scotland at its most magnificent and, as the only home-based, Scots-born passenger aboard, it was with a fair bit of pride I realised that the distances the rest had travelled bore testimony to our country's reputation.
Indeed, those who made the long drives from southern England were joined by Jerry and Linda from America's wild west in Arizona, while Dot and Chris come from just about as Down Under as it is possible to be, in Tasmania.
They had been lured by the Majestic Line's promise of scenery and wildlife and when the Great Glen and the Hebrides are brought into play it is a source of perpetual pleasure to remind ourselves there really are few accessible places on Earth that can match the beauty on our doorstep.
The majority of cruises run by the winners of the 2012 Highlands and Islands Tourism Entrepreneur of the Year award are generally either three nights or six nights in length, taking in the inlets of Mull and Loch Linnhe; the heritage and wildlife of Mull and Glencoe; the Isle of Skye and the Inner Hebrides; Mull of Kintyre and the Inner Hebrides; Loch Ness and the Caledonian Canal; and heritage and wildlife of the southern Hebrides.
For those with a little more time on their hands, a 13-day Outer Hebrides Explorer is an additional option, while the two boats in the fleet, the Glen Massan and its sister vessel the Glen Tarsan, can be chartered for three or six night private cruises.
Those voyaging on these charming converted fishing boats will encounter a design where the emphasis on informality and relaxation sits perfectly with the tranquillity of the surroundings.
While there is a planned route of sorts, weather conditions will be taken into consideration, as will the views of passengers if they fancy a bit of a detour.
For those interested in history there are, of course, all sorts of points of interest. The first morning brought a visit to Kingairloch and a walk along the coastline to a lovely little church adorned by stained glass windows from the same manufacturer as those at St Giles Cathedral in Edinburgh, the task of getting them there speaking to the importance of religion in these parts in the 1800s.
Next day we worked our way up the mainland coast to an anchorage that was just a short distance along the Caledonian Canal tow-path from the striking Neptune's Staircase, built by Thomas Telford in the early 19th century.
Our final day, on Mull, brought a lovely stroll in the sunshine to Duart Castle.
Wildlife abounds in the area, a highlight on our trip being a visit from a shoal of porpoises, while scepticism over Linda's claim of having seen otters at play one morning was more down to the envy of those too lazy in the comfortable berths to have been around to share in the sighting than any real doubts over her integrity as a witness.
Motoring across the water towards the prettiness of Tobermory was another delightful moment, but it would probably be wrong to portray this as a trip for everyone. Some may choose to enjoy an open water dip or head onshore for a run, but these are not activity holidays and going home with a sun tan is unlikely. They are, however, about enjoying a bit of indulgence while getting away from it all.
It feels slightly ironic to say so, given that the interruption to our journey turned out to be down to a faulty battery, but it is hard to imagine a more effective way of recharging.