As we drift in the vastness of the Müritzsee, our trusty boat, the Parchim, feels infinitesimally small. An indignant-looking tern inspects us from buoy 22. On the watery horizon one of the big tourist boats is beating us to Waren. But it is blissful just to soak up the sun, sip our Federweisser – deliciously prickly fermenting new wine – and watch a cabaret of cormorants skydiving for fish.
Also called Das Kleines Meer ("The Little Sea"), Germany's second-largest lake is just one of the numerous spangling Mecklenburg. They are linked by tranquil rivers to form the Elde/Havel Wasserstrasse, the idyllic waterway between Hamburg and Berlin.
A watery web strewn for hundreds of kilometres, it corresponds to the English Lakes bundled with the Broads and then multiplied by 10.
For 40 years, Mecklenburg was tucked just the wrong side of the Iron Curtain, but in 1989 its lake-chequered forests and age-mellowed towns emerged garden-fresh from the Cold War's deep freeze. Its toy-sized capital, Schwerin, is built on the islands of 12 crystalline lakes and is one of Europe's most pleasant cities; the Grand Duke's fairy-tale palace, golden cupolas mirrored in the lake, is incontestably the planet's most beautiful parliament. It was here that Angela Merkel launched her career.
Schwerin's elegant squares, museums and island gardens were our first Mecklenburg surprise; the boats drifting close to our café whetted our appetites for the forthcoming exploration of the region afloat. Our voyage began at Lübz, a tiny riverside town of picturesque old houses, waterside restaurants and rose-scented parks. As with everywhere in Mecklenburg, there lingered an agreeable sense of being in a bygone era, as if the town was still awakening from its two generations of slumber in the GDR's cocoon.
In 1993 an enterprising local boy named Andreas Bockenheuer, his previous job erased along with the border, began renting out canoes here. His firm, now allied with a French company, boasts 20 modern cabin cruisers in a lovely marina. They included our vessel, Parchim. As he showed us the ropes as far as Lübz lock, Andreas told us bookings were booming.
On the still-flowing river Elde we steered from the sun deck. Cornfields alternated with forests; herons ignored us as we floated by; sunlight leaked through the foliage above. Ahead were four locks, but everything turned out to be kinderleicht – easy-peasy. Further along, the bird life absorbed us: cranes, dancing in pairs, wings fluttering like fans. We later learnt that 40,000 of them roost each spring and autumn on Mecklenburg's lake shores. Beyond, we glided into ancient Plau, every crooked house dripping with geraniums.
The six-kilometre crossing of Plauersee was our first stretch of open water. Our manual commanded that we phone base to check the wind speed: too much of a gale and we would risk being beached. All was apparently well, but it still looked pretty breezy out there. I pushed up the revs. Our passage was exhilarating: bumping and bouncing, rainbows spraying on the screen. I felt like a monarch of the waves, until halfway across when I was crassly overtaken by a water-hog speedboat.
We moored for our first night in the island town of Malchow. Frozen somewhere between its medieval genesis and the communist 1950s, its atmospheric cobbled lanes preserved a hidden Germany. A GDR museum showed how Mecklenburgers coped during the one-party regime. High above the town a monolithic Soviet cenotaph was crowned with a fading red star.
One lake led to another: the Flessensee and the Kölpinsee look as small as puddles on the map, but huge when sailing upon them. And entering the Müritzsee was as alarming as Magellan's first gawp at the Pacific. It is immense: 12km wide by 28km long, bigger than Lochs Ness and Lomond combined. Soon the Parchim was scything the notorious Müritz swell; the buffeting and banging offering a syncopation for the Wagner blasting from the radio.
We found the tiny port of Robel marked by two ancient windmills in a fjord-like bay. Its picturesque harbour is hemmed by gardens and fountains. Beside an old inn, we berthed in the new Wasserwanderrastplatz (conveniently abbreviated WWR) – one of the welcoming marinas for water wanderers such as the tired crew of the Parchim.
The ancient town, a fishing port since 1226, is still untouched-up East Germany. Its charm is not yet realising how charming it is. Neglected half-timbered cottages start at €10,000 (£8,300); lakeside villas are a €100,000 (£83,000) snip.
We bought a smoked eel warm from the oven, and a handsome but obscure Müritzsee fish. Both were consumed on deck with local beer and icy Mecklenburg Schnapps as we watched flight after flight of incoming geese against the setting sun.
We almost forgot what living on land was like. The compact boat accommodates a kitchen, lounge, three cabins and two bathrooms, an aft deck, a sun deck and a spacious wheelhouse. Somehow we had managed to fill them. Buying cheesecake from bakers, Schnitzel from butchers and mushrooms from markets, we soon appreciated our bathroom's absence of scales.
The lake's eastern shore follows the boundary of the Müritz National Park for 26km. It is possibly Europe's greatest wildlife wetland, encompassing 100 other smaller lakes. If it quacks, hoots, whoops, swims, flies or dives, it is probably here.
Next day, in the centre of the Müritzsee all was pure tranquillity. Idling the 20km to Waren, the water like a mirror, we were serenely unaware that just below the surface lurked imminent calamity. Juggling wine glasses and field glasses my wife sighted far to starboard the channel of buoys we should have been following – but, I reasoned, it was a big lake. I tapped the depth gauge smugly: 25 clear metres under the keel.
Almost at that moment we ran aground.
There were some heart-lurching gratings and clouds of churned-up sand. Far from terra firma, far from other boats, the Müritzsee looked even most vast than before. My wife was ominously silent. Mortified – no, terrified – I called, sheepishly, faraway Lübz.
Andreas neither sounded surprised nor demanded reparations. Would he send a helicopter? "Can't be deep if it's stuck. Your Frau steers – you must push." In this lake? He couldn't be serious! "Bestimmt doch!" He was.
I stood in water up to my chest while the boat's propeller sliced like a smoothie-maker. I heaved the Parchim back afloat, inch by inch. My panic turned to pride. My wife, half-impressed, refrained from saying: "I told you so."
Coming into Waren, we felt as if we had strayed into the Mediterranean. The town is built on an isthmus between the Müritz and two other lakes. Its steeples and red roofs rise from a parasol-hemmed harbour. Looking dry-cleaned and polished, it radiates that zing of St-Tropez or Portofino. A pair of market squares, a medieval town hall, shops and promenades make a heady cocktail for sailors fresh ashore.
Waren has been a favourite resort since Germans first took holidays. During the years of sealed borders, it offered East Germans their own taste of the Med. Even today, foreigners are so rare that shops sell postcard stamps only for Germany.
The freshwater aquarium houses many of the species of fish that had been swimming under our boat. Many, such as the giant catfish, we'd already had on our plates. Restaurants were everywhere. With a bottle of chilled riesling we watched the moon on the water while the quayside café's candles twinkled like stars. In the next berth a couple in evening dress were dancing on deck.
The closest airport is Hamburg, which is served by Lufthansa (0870 837 7747; www.lufthansa.com), British Airways (0870 850 9850; www.ba.com), Flybe (0871 700 0123; www.flybe.com), OLT (00 49 4921 89920; www.olt.d) and Germanwings (0870 252 1250; www.germanwings.com).
Alternatively, you can take the train from London St Pancras or Ashford to Hamburg, changing at Brussels and Cologne (0871 880 8066; www.bahn.co.uk).
To reduce the impact on the environment, you can buy an "offset" through Abta's Reduce My Footprint initiative (020-7637 2444; www.reducemyfootprint.travel).
Blue Line Charter, Schulstrasse 8A, Lübz, Germany (00 49 38 731 22 428; www.blue-line-charter.de). Charter starts at €1,270 (£1,058) per week for a five-berth boat in the Mecklenburg region. The same boats are available to charter from the affiliated French operation Nicols (00 33 41 56 46 56; www.nicols.com), which has a website in English.
Müritz-National Park (00 49 39 824 2520; www.nationalpark-mueritz.de).
Mecklenburg Tourist Association: 00 49 39 93 153 828; www.mecklenburgischeseenplatte.de
German National Tourist Board: 020-7317 0908; www.germany-tourism.co.uk