The boat is a much-modified 5 metre Catapult catamaran. Her lightweight of 90 kilos and car-top portability aids exploration of distant areas, conceptually 'backpacking by boat'. Shelter is always assured, for the tough inflatable hulls permit beaching virtually anywhere. Her rig is a 10 square metre battened main on a wish'boom, a 3 square metre jib and an 18 square metre spi on a jib ‘boom - reefing and furling - hauls out at night. Wing slings on wires, for relaxed sitting out - gear stows in waterproof bag on the tramp. Top-range warm clothing, drysuits and snorkels, good sleeping bags with a four season tent. Boil-in-bag munchies, Glenlivet miniatures, one-burner gas stove and wine of the month. Scotland and Solent, Corsica, Cornwall, Norway and Baltic - she's tough as old boots.

It was the gunboats that woke us. Their supercharged diesels roared out of the early mist, sweeping past close inshore not 100 yards from where we lay asleep on our little Catapult, pulled half up on the beach. First one then four, huge breaking wakes surged towards us as we struggled out of our sleeping bags. We had pulled our boat ashore just after midnight on the remote island of Bla Jungfrun - the Blue Maiden - a dozen miles off Sweden's east coast. Eleanor and I were dinghy camping up through the eastern archipelago towards Stockholm, and were about to be wrecked on the beach by the Swedish navy.

One by one the waves surged in, steepened and collapsed onto our little boat, washing all our gear into a soggy heap among the boulders. "Eina!" yelped Eli in her mother tongue as we scrabbled barefoot in the shallows to hold down our leaping boat. "This is no way to wake a lady!" Somehow the hulls survived although showing some scrapes and scratches, and we spent the rest of the day exploring this uninhabited, little visited isle and its ancient rock labyrinth, wondering about the lingering tales of pagan practice, whilst our cuts and clothes dried in the sun. Our way lay north, deep into the vast archipelago guarding the length of Sweden's Baltic coast. Huddled from the east winds of winter onto the few islands with water is a handful of tiny communities of fisher-folk; each smoking their catch on oak chippings and a secret mix of special herbs during the brief Baltic summer. Here is one hundred thousand islands - some a score of miles long, many just a score of yards - home to a million sea birds in protected refuges - and just a few hundred seals, sad remnants of the huge colonies once hunted to near extinction.

Day on day the sea breeze blew, carrying the warm summer smells of fresh hay and flowers from the Baltic isles of Oland and Gotland just over the horizon, deeper into the maze of isles and skerries we roamed. Snuggo and Vino, Kroko and Haradskar. Each gold dawn a flurry of sea birds and a bright new promise, each island evening still in the glow of our driftwood fire, grebes calling, and the moon glinting and gleaming on the quiet waters. Here, deep in the heart of the outer isles, we stumbled on one of Sweden's closest secrets. Threading a chain of passages, the reefs now jagged where before they had been round, we spotted a small boat slip behind a rock and disappear into the trees. Following, we found ourselves in a hidden lagoon near-filled with heavy moorings. Alongside the cluster of huts ashore were a handful of powerful launches - most in the grey and black paint of the coastal, marine guard - while moored in the deeper water were three of the navy gunboats encountered a week before.

"Hoi!...Hoi!" came shouts from the shore, "Come here! We'd been spotted. What had we stumbled on, flying our red ensign and MOCRA/DCA pennants? - a special forces training camp? - a secret defence base? - would we be arrested? We quickly discovered this was Thures Uddes's famous "Fisk Rokeri" - the source of the finest smoked fish in the Baltic and home to an old buccaneer whose exploits against the Germans and others are still legend to the Swedes. We had just gatecrashed a highly informal naval drinks party, celebrating some old battles or new promotions, in one of the few places in Sweden where the bar don't close and the drink flows free! - and I mean free, for it had recently been impounded from smugglers, so when we produced some duty-free Glenlivet from our sacks, we were invited to participate in an old Viking custom Skall .... slainthe .... prosit .... cheers ". The illicit aquavit and vodka passed swiftly from hand to hand. Old Thure's sitting room became the packed centre of the party, his green enamel log stove glowing far into the night. The bastu/sauna behind the store held the overflow, while a continual stream of glowing, beaming Swedes - men, women, even some children - swirled to and fro, first in tracksuits, then in towels, then not ... From boat to sitting room to sauna.... "Strewth! You don't see this at the MOCRA Nationals!" hissed Eleanor. We made our excuses and crept away, not quite at dawn, to find another little island on which to crawl into our bags and nurse our poor heads. The answer was to return to the sauna, but we feared for our souls....

The storm caught us working our way up the lee of a chain of islets at the mouth of the Braviken Gulf, a 25 kilometre open passage on our route northwards. From three-sail reaching and running free, the pattern of the previous two weeks, we were down to deep-reefed main, luffing hard towards shelter as each new squall howled down at us between the islands. We battled to windward, for there was nothing down to lee except rising wind and waves. Each time we were forced out round the end of a long gill net or outlying rock, I fought to recover the lost ground and make up towards a little wooded islet on which we could shelter. At last one squall veered enough to give us the slant we needed, and we dived into a cleft in the rocks, Eli scrambling ashore with our mooring line. In no time we had our little tent up, deep among the twisted trees, mainsail tied over as a flysheet, our boat and everything else hauled onto land and lashed down. The spray flew right over us in sheets, and even in the lee of the trees our boat's rigging hummed and moaned all night. But we were warm - and dry - and ashore.

Next morning, as we left in a cold westerly breeze, the sea still running high, a large black shape soared out from behind our island. We had shared our shelter with a rare solitary sea eagle, well over 2 metres in span, which escorted us, circling, along the chain of rocks and skerries for a couple of miles or so until: the only sail on the water, the open gulf lay ahead. Bowling along smartly as the sun climbed and the day warmed, we fetched the little town of Oxelosund a planned staging post, by midday. The local dinghy club took charge of boat and gear, hauled out on their slip, while we went in search of a shave, shower, shampoo, hot meal, cold beer and a bank - not necessarily in that order! During the third cold beer, and while writing up our notes for the past 150 miles, we realised we had passed out of the Bla Kust archipelago, the coastline was now running away east towards Stockholm.

Now there are two sea routes to Stockholm. One runs round the coastline in a 130-mile arc, approaching from the east. This passes through a chain of seriously sensitive military areas and we had been warned! The other takes a shortcut up the 40 mile Himmerfjarden, through a lock into the Malaren inland sea, then a right turn takes one down into the heart of the city - by the back door. This is one of Sweden's loveliest areas - the waters' edge lined with weekend cottages, characteristic brown-stained wood, the national flag on a pole, green lawns and little jetties.... and a different kind of seal.

Whereas the whiskered grey/brown variety in archipelago had been shy, slipping away as we passed, this species basked in the sun from mid-morning right through the afternoon, stretched out on little jetties or on the rocks to one side, their golden pelts and long blond hair gleaming in the sun. Hiding behind their sunglasses, uttering their calls of "Hi.... Hi" at our approach. These most prolific of Sweden's marine mammals preened and oiled themselves while awaiting their mates' return at day's end from the city.

And so we sailed into the heart of Stockholm - spinnaker, pennants and flags flying in the sun - past embassy lawns, under the motorway bridges and between the parks to find ourselves in front of the parliament and the towers of the royal palace, rounding up finally alongside Barbara Hutton's fabled yacht Mallardrottiningen, where the aristocracy and royalty of Europe once loved and played. Now a luxury hotel, this elegant old boat was host to us - little Catapult alongside - as we dined on the afterdeck under the stars, savouring our first evening in 'Royal Stockholm' and the end of our 250-mile voyage of exploration.