Bring plenty of olive oil - then chuck it down the ship's toilet

Yes, tugboat 'Billy' is a little eccentric. But Rachel Spence wouldn't have cruised Burgundy's Yonne river in any other vessel

'Jump! Jump!" My partner yells, urging me to leap on to the canal bank. Our boat Billy has other ideas. Stubborn as a carthorse, he swings

'Jump! Jump!" My partner yells, urging me to leap on to the canal bank. Our boat Billy has other ideas. Stubborn as a carthorse, he swings

his prow over to the other side of the lock. As the water leaks out through the gates, Billy sways alarmingly while I struggle to extricate myself from the tangle of rope.

Our butter-fingers are no surprise. Only the day before, we were canal-boat virgins. On arrival at the port of Vermonton, a pretty town whose limestone houses are buried among the vine-covered hills of northern Burgundy, we sought out the offices of pleasure-boat company France Afloat.

Our guru was Steve Adam, a Kent man who runs the business with his family. As we walked past the boats tethered on the bank - from shiny white cruisers to sailing boats - it was hard to tell who was more unflappable: Steve or the millpond-still Nivernais canal, upon whose waters we were about to be let loose.

Billy might not be the grandest boat but he is certainly the cutest - think tugboat meets Victorian bathtub. Into his 20ft by 10ft frame, some ingenious boat-builder had squeezed a kitchen, seating area, shower, loo and double bed. A pocket-sized terrace at the stern permits alfresco dining.

Steve's briefing rivals an Everest Sherpa's for intensity. Among a host of dos and don'ts, the scariest was an injunction to put olive oil down the loo to stop it clogging. Driving looks easy until we realise that Billy's reflexes are tortoise-slow, and the only way to brake is go into reverse: "But then there's no steering," adds Steve cheerfully. Haunted by the woodwork teacher who enjoyed highlighting my abject failure to follow practical instructions, I whisper to J: "You drive, I'll cook."

Yet, once out on the water and through a couple of locks, all anxieties evaporate. Twenty-first-century life - cars, computers, all things electric, including mobile phone chargers - has been left behind on the Vermonton dock.

The landscape is hypnotising. Following the course of the river Yonne, and sometimes converging with it, the Nivernais canal was dug in the 19th century to assist the flourishing logging trade. As the barges ferried their precious timbers from the Morvan forests to the woodyards of Paris they wound their way through the hills and valleys of some of Burgundy's finest countryside. Today, the towpaths are deserted save for the occasional family out for a cycle ride.

We pass fields of sunflowers and vine-covered slopes laden with pinot noir and chardonnay - you'll find finer only in the Côte d'Or to the south.

The river is another world entirely. Tiny fish swim in her brown-green depths; ducks and swans skulk in the shallows; herons swoop frequently across our path; cicadas chatter in the trees. A sleek black head scythes through the water: it's an otter, the first either of us have ever seen.

With just four days at our disposal (most holidaymakers would take a week) we aim to arrive that evening in the city of Auxerre, some 15km up river. Hugely pleased with ourselves, we glide through the final lock at dusk. It's a magnificent way to enter a city which, since Roman times, has built its prosperity on the river that runs through it.

And the sight of Auxerre is worth the six-hour - and 17-lock - journey. Built on the steep hillside which overlooks the east bank of the Yonne, it is an unspoilt medieval metropolis of tall, Burgundian roofs and golden stone dominated by the majestic cathedral of St-Etienne.

The mooring point, however, looks daunting. Some 20 boats are already neatly parked and only one small, just-about-Billy-sized space is free. Remembering Steve's warning about steering backwards, J and I grin weakly. Billy, meanwhile, simply turns circles in the middle of the river.

Fortunately, if there's one thing boat people like more than driving their own boat, it's helping hopeless amateurs to drive theirs. Within seconds, people are issuing instructions from the bank. Conscious of professionals in charge, Billy obeys meekly and is soon lined up with everybody else.

Next it's a quick gallop to the shops. We go for regional specialities - snail pie, Epoisse cheese, a roasted Bresse chicken, salad, crusty bread - and an all-important bottle of local Irancy. Then we repair to Billy's terrace and watch the sunset.

In the morning we plunge into the steep, cobbled streets of Auxerre. Truly a city of the river. The historic heart is dubbed the Marine quarter and there are still streets, with names such as Rue de l'Yonne and Place du Coche d'Eau (Passenger Barge Square), lined with the half-timbered homes once lived in by rivermen. Also impressive is the cathedral, a flamboyant Gothic affair, like a miniature Chartres, with vertiginous vaulted ceilings, flimsy columns and an intricately carved façade - blame the 16th-century Huguenots for lopping off the heads of the naive stone figures on the arches. Take time also to visit the Carolingian crypts beneath the Abbey of St-Germain, where the trio of frail, ninth-century frescoes are believed to be the oldest in France.

Over the next couple of days, we potter south again, wine-tasting en route. One afternoon, we moor below the Caves du Bailly where the awesome 800-year-old galleries extend deep into the cliff and are home to about five million bottles of fizzy wine. This is Crémant de Bourgogne, made from a chardonnay grape yet as dry and delicious as champagne and half the price.

Further inland lies Saint-Bris. This hilltop village, surrounded by vineyards and cherry orchards, is famous for its own appellation sauvignon but also produces fine burgundies. We pause at the caves of the Bersan brothers, whose family has been making wine here since the 15th century. The warren of damp, dark vaults are an oenophile's paradise with mould-encrusted bottles in every alcove; oak casks containing both burgundy and Chablis, and the original grape press.

After we've tasted their sauvignon de Saint-Bris 2001 and an oak-aged cuvée spéciale 2001, M. Bersan explains how delighted he is that the town won its appellation in 2002 so that now the burgundies will also carry the name of Saint-Bris too.

As dusk falls, we moor at the tiny village of Vaux. No worries about oversleeping - the quacking of the ducks proves a most effective early-morning call. A visit to the only shop procures a fresh baguette for our breakfast. No electricity means no TV and radio noise from the other boats, just the clinking of cutlery and the smell of fresh coffee.

It's a blisteringly hot day; just beyond Vincelles Islip into the Yonne. As I stroke my way through the clean, cool water, the sun falling through the dark trees, my only companions are the boatmen and the dragonflies.

It's impossible not to be won over by the charms of the Yonne valley. Unlike the Loire, Lot and Dordogne, it's almost tourist-free - apart from the pleasure-craft crowd, of course, and even then you can cruise for hours without seeing a boat. Yet the banks of the Yonne are overlooked by treasures - from land-that-time-forgot villages, with pale-shuttered, limestone houses and minute Romanesque churches, to splendid fortified towns, such as Châtel-Censoir and Mailly-le-Château, whose medieval curtain walls are the legacy of Burgundy's days as a powerful duchy. And just half an hour's drive north lies prime Chablis country.

Good restaurants abound in Burgundy, and on our last night we treat ourselves to the full works at Vermonton's Restaurant du Parc, where the set menus ensure decent value and you choose your own bottle of wine from the cellar. Here £12.50 buys you four courses starting with a sumptuous oeufs en mourettes (eggs in red wine), and finishing with a tarte tatin.

Saying goodbye to Billy is much harder than leaving a hotel. I find myself hoping his next tenants will treat him properly. I also find that, once back on dry land, I miss the river: its sounds, sights, smells and, most of all, the sense of peace.

The Facts

Getting there

Rachel Spence cruised courtesy of France Afloat (08700 110 538; www.franceafloat.com). A week sailing the Nivernais Canal costs from £475 per boat per week. P&O Ferries (08705 202020.; www.poferries.com) operates five crossings daily between Portsmouth and Cherbourg. Exclusive travel supplements from Hoverspeed, P&O Stena Line, P&O Portsmouth and Eurotunnel are available as part of a France Afloat package holiday. Secure parking costs from £13 to £27. Bikes can be hired for £20 each. France Afloat also organises canal cruises in the Loire, Midi, Brittany, Camargue, Aquitaine and Champagne.

Being there

Domaine Bersan 7 Fils, 20 rue du Docteur Tardieux, St-Bris-le-Vineux (00 33 3 86 53 33 73). Les Caves de Bailly, St-Bris-le-Vineux (00 33 3 86 53 77 77. www.caves-bailly.com). Restaurant du Parc, RN 6 - 89270 Vermonton (00 33 3 86 81 51 51). Closed Tuesday evening and Wednesday.

Further information

Auxerre Tourist Office, 1-2, quai de la République, 89000 Auxerre (0033 3 86 52 06 19; www.ot-auxerre.fr).