Twenty-four thousand islands, one slow boat.

Late September: the last calm window

The forecast promised a high sitting over southern Sweden for three days, and for once it delivered. Launched just after eight from the usual gravel ramp, water at twelve degrees, air barely warmer. The first hour through the inner channels is always the same: ferries, a few motorboats heading out to close up summer houses, and a heron that refuses to move off the same buoy every single time.

Past the last big island the fetch opens up and the swell comes in long and lazy from the south-east. Nothing dangerous, but enough that the boat starts talking to you. I stopped on a bare granite slab for coffee and watched two eiders drift past with complete indifference.

Day three is the reminder I keep needing: the front arrived about four hours before the model said. I had a short inside route planned as an escape and used it.

August: fog, and learning to trust the compass

Morning fog in the archipelago can be so thick you lose sight of your partner's bow at twenty metres. We had planned an easy two-kilometre crossing to the northern island group, and it turned into forty minutes of paddling purely on a bearing, stopping every few minutes to listen for engines.

What helped: agreeing before launch on the bearing and on a turn-back time, keeping the boats close enough to talk, and a small horn clipped to the deck. What didn't: my phone, which chose that moment to decide the screen was too cold to respond to wet fingers.

• Write crossing bearings on deck tape the evening before.
• In August the fog usually burns off by late morning — sometimes waiting two hours on the beach is the smartest paddle stroke.
• Big ships keep to the marked lanes; cross them at right angles, together, and quickly.

July: the "tide" that isn't

People coming from the North Sea always ask about tides here. The Baltic barely has any, but the level still moves: a steady wind for a few days can push the water up or down by half a metre, and air pressure does the rest. That's enough to turn a shallow sound you remember as easy into a boulder garden.

The narrow channels also run with a real current after a hard blow — I once spent twenty minutes ferry-gliding across a sound that looks like a pond on the chart. Ask local paddlers about the spots that surprise them; everyone has two or three.

June: first overnight of the season

Every season starts with a shakedown close to home: repack everything, find out which dry bag leaks this year, remember how the tent goes up in wind. This year's lesson: the new sleeping mat is noticeably colder than the old one — fine in June, miserable in September.

Midsummer light is its own thing. It never gets properly dark, so I paddled until nearly eleven along a sheltered channel with the sun sitting just under the horizon and every island mirrored in the water.