Five hours out of Kokkola, the Baltic was baring its teeth. It was the middle of the night in the middle of June. The air temperature was below 5°C and our progress to windward was slow against the short, hard, grey Baltic waves.

I wondered a few times where the charm of this place lay. The sky at midnight was the shade of a dreary day in Britain and we were entirely alone in the Gulf of Bothnia. It felt as though we were gaining no ground; as though the trip south would take forever.

When I’d arrived in Finland to deliver the newly refurbished Swan 43 Runn south with her owner, Charles Hill, and a crew of friends, I had no idea what to expect. My only points of reference for the Baltic had been a sunny trip to the beach in Poland and a winter weekend in Stockholm.

Runn had spent just over the last year at Yxpila boatyard close to 64°N, just 130 miles short of the Arctic Circle, where winters offer only three hours of daylight and boats are kept in sheds that are so well heated you can work in shorts and T-shirts.

Our summer delivery was intended as a shakedown for the boat post-refit and as a relocation south for family cruising, as well as a chance to take in the Swan 50th anniversary regatta in Turku, Finland.

On our leg we had to make 300 miles south, finishing in Stockholm, where a new crew would arrive to complete the voyage. We had eight days to explore the coasts on both sides of the Baltic, but during that first night we began to feel the whole cruise would be spent in thermals beating against stubborn conditions.

Guide to cruising in Sweden: Long summer days and easy sailing

Avoiding the dangerous Kvarken

Our first destination was predetermined: we were to head to the Swedish side of the gulf to meet a man call Ulf at his summerhouse on the island of Ulvön. This had all been set up by the boatyard manager, Sven. Ulf was going to loan us his paper charts of Sweden to save Charles having to buy the volumes that covered the myriad of islands along this coast.

We had Finnish charts to cover the trip and would rely on electronics to get to Ulf. The co-ordinates of his house (along with his phone number) were written on a piece of paper.

Navigation for the first part of the trip looked easy enough on paper. The Baltic was empty and although the course was to windward, we intended to strike out into the centre, giving us room to learn to sail Runn properly in moderate conditions that seemed made for the boat.

Then Sven came to see us off. First he advised us not to rely on the channel marks as our sole pilotage aids; the posts could be out by quite a few metres, he said, because the ice that came down the gulf in winter shunted them out of position. Not what you want to hear about timber poles that mark fairly dangerous rocks.

Second, he gave us a dire warning about our plan to sail directly to Sweden. The Gulf of Bothnia narrows into the Kvarken, a two-mile gap between the off-lying islands of Finland and Sweden. The depth here drops to 15m and all commercial traffic funnels through the same channel that we had planned to pass through.

With the 20-knot forecast this had seemed viable to us. Sven clearly thought we were either crazy or ignorant. The sea states would be violent and the passage dangerous to pass, he said. This was not what the Finns did.

With his warnings ringing in our ears, we decided to head instead down the Finnish coast, then make our way through the small archipelago off Vaasa before striking west, well clear of the dreaded Kvarken, in search of Ulf.

The lighthouse of Öregrund continues to wink, even in the half-light of a midsummer night.

Sailing Runn – the delights of a Swan 43

We were a crew of five who had never sailed together before, on a boat that was just out of refit. We wanted an easy start. So, we headed off through the tree-lined channels to the open water of the Gulf of Bothnia.

At these latitudes the midsummer sun only sets for a couple of hours, so night is just twilight. And as the day had been overcast, so was the night – a cold, grey day slipped into a cold, grey night.

Yet Runn was beautiful to sail. The aggressive waves picked up by a steady 20-knot wind seemed to be absorbed by her hull and she was graceful – unlike the crew swaddled in winter thermals and full foulweather gear. The more we sailed, the better we got – learning how high we could point, how to take the waves – and we arrived at the entrance to the Vassa archipelago slightly sharper sailors than we had been the evening before.

All hands were on deck for our first taste of archipelago navigation. Armed with paper charts, a B&G Zeus plotter and an iPad loaded with Navionics software, we had all bases covered. The islands are tiny. The more you zoom in on an e-chart, the more of them you see. It looks like a leopard print overlaid on the sea. Paper charts are cross-hatched with bearing lines that indicate the countless leading marks and back-bearings to pilot you between rocky outcrops via tiny channels, some just a couple of boatlengths wide.

The islands were a surprise for me. From the chart, I had imagined jagged cliffs and striking scenery. Instead, the islands were flat and covered in pine trees. There was little sign of habitation and although there were a lot of islands, the lack of variety made things a bit dull.

Making our way through the channels was anything but dull, however. We had a dedicated navigator below while the rest of the team spotted posts, striped rocks and leading marks; this maze of islands can easily spring a nasty surprise unless you are on the ball. To complicate matters, the uniformity of the scenery makes it almost impossible to distinguish where you are looking.

We sailed where we could and motored when the width of the channel would not allow it, popping back out south of the Kvarken and ready to renew our search for Ulf. With the breeze on the beam, Runn was finally able to stretch her legs and we were treated to an easy overnight passage under full sail, and had time to figure out the three-wheel system that operates her rudder and trim tab.

We made a landfall on the Swedish side in a grey mist in the early morning twilight about 0200, just before sunrise. We had received news from Sven that the weather was bad, so Ulf was not in his summerhouse but in the town of Örnskldsvik up a fjord.

The lighthouses on the Swedish side continued to work even in the half-light, and we navigated our way up ever-narrowing channels using a well-designed system of sectored lights. Foreshores were studded with rounded not jagged rocks. Wooden-framed houses and boat docks were scattered along the shore. Sweden already looked different from the coast across the water.

We anchored in a small muddy inlet just outside the Örnskldsvik and slept until Sweden woke up. In the morning we would head into town and call Ulf.

It turned out that he had been tracking us on AIS all the time; making sure the silly English did not head through the Kvarken, perhaps. He appeared in a huge black RIB in the morning and led us into a brand new marina at Örnskldsvik.

Sunset for our landfall at Öregrund… at 2300!

Cruising in Sweden – amazing facilities

First, there were a couple of jobs to do after our first sail. The wire halyard for the genoa had broken and needed a new swage fitting. We also needed a new house battery and water and fuel for the rest of the journey south. The Swedes everywhere were kind and helpful. Complimentary, too: everyone who came across Runn commented on how beautiful she was. We even met two men who had worked in the Nautor’s Swan yard in the 1960s and 1970s who said they had sailed her when she was first commissioned.

The Swedish style of doing things is as thorough as you’d hope. Quality is high, no corners are cut. In addition, the new marina building had enormous semi-automatic doors to protect us from the cold and included two full kitchens with crockery, pans, dishwasher and washing machines, all free to use for marina guests.

With charts galore, we left Örnskldsvik, keen to make some miles southward on another grey evening. But the cloud cleared and we headed out in our first sunshine since we arrived in Scandinavia on a flat calm sea. As we motored out through the island chain, the sun high in the sky at 2100, we received a glimpse of just how beautiful this stretch of coast could be.

The rocks were a thousand soft shades of brown, pink and red. The flat sea reflected the blue sky perfectly, and every house on the shore was pretty. Incredibly, we were still the only people on the water and we drank in the sun and the scenery on an endless summer day.

With no wind, we motored south in sunshine. Charles put his crew to work, setting up the new spinnaker gear, whipping rope ends and making eye splices. We settled into single-person watches, with plenty of jobs for the rest of us to do. By the time we arrived at our next stop of Öregrund we had completely lost sense of time. When there is no true darkness and your life is contained within a small sailing boat, the boundaries between night and day become irrelevant.

We made landfall just as the sun was starting to set around 2300. We found the town and tied up to a pristine empty berth. What else to do then but fire up the barbecue in the cockpit?

We were treated to a breathtaking all-night sunset. The sky changed from orange to pink to purple, then back again as the sun set then rose again at around 0230. Even the mosquitos which nipped at our ankles couldn’t spoil the mellow mood. It was quite a show.

Calm seas and sunny evenings (this was taken at 2100) in the Stockholm archipelago.

Stockholm archipelago

The final leg of our voyage would take us into the northern part of the Stockholm archipelago. No one knows exactly how many islands there are in the chain. The most commonly cited number seems to be 28,000, and entering from seaward the scale of what is ahead blows you away.

We found a wide, easy channel to start with (there was no point rock-hopping until we had the measure of the place). The sun was shining, there was a 12- to 14-knot breeze, the water was flat and the islands were perfect. The beauty of the place hit us square on.

The archipelago’s beauty is not of a stunning sort, but one that’s gentle and faultless for mile after mile. Looking in every direction was delightful. Nothing spoiled the view. Even isolated rocky humps sticking out the water looked soft and had a pink hue.

As we picked our way through the islands towards Stockholm, the water became busier and shorelines more populated. So, we decided to stray out of the main channel and search for an anchorage where we could swim, barbecue and make the most of our surroundings.

You could spend years in this archipelago and be alone in a different anchorage on every night. The intricate shapes of these islands, with their small inlets and tree-lined coves, ensure you can find complete calm in every wind direction, and, provided you don’t hook an underwater island power supply (well marked, thankfully), there are no limits to where you can go. ‘Go where you want, so long as you don’t upset others’ is the Swedish policy. You won’t run short of options.

Day ran into night and once again we lost all concept of time and had another overnight sunset and barbecue well into the early hours of the morning.

Our final weekend coincided with midsummer celebrations in Stockholm and one of the hottest days of the year. As we made our way towards the capital, the channels started to fill with small sailing and motorboats full of people. Commercial boats were decorated with tree branches for the occasion, as is the Swedish folk custom, and busy stretches of water started to become noisy with the sound of engines.

With only one day left, we wanted to try out both of Runn’s new spinnakers. So, we found a wide stretch of water near the island of Vaxholm and set to work on a few hoists and drops. After our days of solitude, the water seemed crammed with other vessels – the boats here were quite a lot smaller than those we see in the UK and had a lot more people on board. But in reality it was no busier than one of our own yachting centres in summer.

We practised spinnaker procedure with no problem, other boat owners were considerate and when a large motorboat did come too close, making a large wake, a Swedish Coastguard vessel appeared with flashing lights and a siren from around the back of an island, pulled the driver over and appeared to be issuing him with a fine.

The air temperature was now into the 30s – it seemed absurd after the single figures of six days earlier. We hunted out another anchorage and jumped into water of 11°C to cool off. Only once we were in did we notice that there were no sensible Swedes in the water.

As we left the boat in Vaxholm it felt as though we had spent a whole season in the Baltic, such was the difference between the sparse, cold north Finnish coast and the bustling, warm Stockholm archipelago.

Either way, I loved the long endless days. They made me feel as though anything was possible and you could get more out of life.

It’s not hyperbole to suggest there really are endless options for exploration in the 120-mile stretch of the Baltic between Stockholm and Finland. It’s so crammed with islands that you could never get to visit them all. I think we saw the place at its sun-drenched best. But even in the rain and wind I would be happy to hunker down there in a quiet anchorage with a cup of tea and a good book. This is a place to keep the world at bay.