From its 10 million-year-old home, 227-metres down, it came from the deep. First there was a ripple followed by a wave and a bubble. Then froth. And then it emerged, surfacing through the grey cold water. First, a small head and then a slender neck.
Its mouth gaped, displaying a picket fence of primeval dentistry. In all, from its head to tip, I estimated it to be about 163m and weighing around 57kg.
I would recognise my wife anywhere. Even swimming in Loch Ness, which is 37 0149km long and has more fresh water than in all of England and Wales.
At the Loch Ness Exhibition Centre at Drumna-drochit you learn that "Nessie" was first spotted by St Columba in AD565 but the myth only took hold after blasting operations to upgrade a shore-side road and a photo by a gynaecologist in 1934 which some saw as a prehistoric monster and some as a stick wearing a surgical glove. A South African tourist's 16mm film shot in 1938 further bolstered the reputation of the Loch.
One hoax involved using a hippopotamus foot table.
In the stylish Centre you are desensationalised and learn the Loch has an average depth of 132 metres and has very low visibility due to its high peat content. It is also subject to mirages. So sightings of strange objects can be explained by boat wakes, windslicks, floating logs, rocks, debris, swimming deer or multi-humped wives in far-too-tight M&S bathing costumes.
If you are lucky you may meet naturalist Adrian Shine on the water's edge. He has been studying the Loch for 30 years.
"It's a hidden world," he told me over shortbread. "Enough water to immerse every man, woman and child in the world three times over. So room enough for a mystery."
He believes if there is a big fish it may be an Atlantic sturgeon.
Although he is keen to de-Nessie Loch Ness, he admits there is an enduring mystery: "If a monster exists then science has ignored the most exciting wildlife mystery in UK. If there isn't one, 1 000 people, including a saint, have lied!"
The Drumnadrochit Hotel (owned by the Bremner family) is inextricably linked with the Nessie phenomenon. In 1916 a local gamekeeper came in "as white as paper" claiming to have seen a huge fish.
In 1933 the manageress, Mrs Mackay claimed she had seen a whale-like object breaching in the loch. In 1993 there were three sightings in one night. The only humps we saw in 2007 were from the kids when they couldn't go quadbiking.
Not seeing the infamous monster is not the only thing you can do in north Scotland. Invernesshire has many other attractions. You can visit the battlefield at Culloden (1746), play golf at Royal Dornoch or Nairn, visit weaving exhibitions and factories as well as Britain's most active earthquake zone at the Great Glen.
Glenmorangie offers tastings at its distillery in Tain as does "the perilously drinkable" Glen Ord whisky. And the world's most northerly winery at Moniack Castle which specialised in Prince Albert's favourite tipple, silver birch wine.
Perhaps the best and most relaxing way to see Loch Ness and the Highlands is to cruise along the Caledonian Canal. Originally built in 1822 by Thomas Telford as a short-cut between the North Sea and the Atlantic to avoid the dangerous Pentland Firth, it is the latest waterway to be opened up for holidays afloat. It runs for 97km from Clachnaharry on the Moray Firth through the Great Glen to Corpach on Loch Eil. Thirty-five kilometres connect the lochs of Dochfour, Ness, Oich and Lochy.
The journey from Inverness to Fort Williams takes a minimum of three days sedately passing through some of the finest scenery in Scotland and past ancient clan burial grounds and the sites of clan battles like the Battle of the Shirts fought at the end of Laggan Avenue between Lochs Oich and Lochy.
Caley Cruisers is run by Audrey Hogan. Her father Jim, a garage owner, pioneered boating holidays on the canal when he started the business in 1970 renting out the boat. He appears now and then to hold your line for you as you pass through the locks. The firm now boasts a family-friendly fleet of 40 boats and 12 classes from the top-of-the-range Balmoral (complete with flat screen and DVD) to the smaller Brodie and Iona class.
Says Audrey: "The only strange things I've seen on Loch Ness are what some customers do with their boats! But it's all very plain-sailing. The lockkeepers are all helpful. Safety is paramount and we do advise life-jackets on at all times."
The Hollywood Loch Ness movie was actually filmed mostly in Ireland. But you will see Urquhart Castle as well as other castles along the way like Aldourie, Achnacary, Inverlochy and Great Glengarry.
You will pass places like Ach an Todhair (Field of the Manure), Alltsigh (Burn of the Bitch) and Meall Fuar-Mhonaidh (The Mound of the Cold Moorland) from which the whole of Loch Ness can be seen and the journey's end is Neptune's Staircase at Banavie (Place of Pigs).
You will impress your friends when you tell them you have just been on holiday to the Place of the Pigs and Neptune's Staircase. They will think you have been to Cuba and into outer space.
There are plenty of hostelries en route. Caroline Gregory bought the Lovat Arms at Fort Augustus in 2006 with her father David.
Chef Jim Murphy offers seared scallops with Fort Augustus black pudding as well as Angus beef and poached Lochaber salmon. Fort Augustus' The Boathouse Lochside Restaurant set in ground of St Benedict's Abbey offers Speyside meat and Mallaig fish. Highland venison stew is the house speciality. Glengarry Castle Hotel on Loch Oich and The Clansman on Ness are also recommended. Forty-two lock gates build up a thirst and an appetite.
The chains seen on some locks go back to the times when sailing ships used the canal.
The chains prevented the ships from colliding with gates. The locks became fully mechanised by 1969 and are not to be feared.
If you have a low venison and haggis threshold, all the boats are equipped with a galley. En route you can fish, walk the tow paths or scale Ben Nevis, Britain's highest mountain. There is a gondola for the lazy. There are three golf courses and riding available at Drumnadrochit and Tourlundy Farm. Most people sleep on board.
The game most people play is looking at the faces of crew members change colour according to the wind velocity and sun. Or lack of. In an hour cruising the open waters my face gave a very realistic impersonation of a Graham of Montieth tartan. My wife's was - we decided - Chisholm Hunting tartan while the kids were Macdonald and Fraser.
From beneath us it came
On the last night we had a hearing rather than a sighting. From beneath us it came. The sound of some prehistoric plesiosaurus. We went below to investigate and found Mrs Pilley snoring away, her head propped up on her buoyancy aid. You didn't need to be a professor of cryptozoology to know a knackered but content, cold-blooded reptile when you heard and saw one.
She has always been a natural phenomenon.
- More info from