Saturday dawned bright and sunny, and, with a morning at sea, we enjoyed a more leisurely start to the day. It began with a talk on the evolution of boats in the Baltic, tracing the similarities in design and construction from prehistory up until the post-medieval era. Shortly after, the pilot boat came alongside and we entered the Swedish archipelago, gently winding our way between the hundreds of islands east of Stockholm. On such a lovely sunny day, thousands of locals had also taken to the water. As we steamed into narrower channels, we were surrounded by vessels of all sorts, from traditional sailing ships to ferries and pleasure crafts.

After another talk, this time looking at the Baltic’s geology and hydrography, we passed through the narrow Oksydypet Strait. Marking the entry to the main channel into Stockholm, the strait has been well guarded since the 18th century. The complex Fredriksborgs Fortress on the east of the channel was completed in 1735, and was reinforced in the 1870s by the Oskar-Fredriksborg Fortress on the west bank. Although separated by less than 150 years, the rapid evolution of armament technology in that period means that the two forts are radically different in design and appearance.

Our pilot then took us off the main channel so that we could pass by the island fortress of Vaxholm. Fortified since the 16th century to defend Stockholm’s approaches, the site was extensively redeveloped in the early 1800s, creating a huge fortification that stands guard over the entire channel. Although eventually superseded by the fortifications at Oksydypet, Vaxholm is well preserved and is now a museum.

Later in the afternoon, we entered Stockholm itself. A busy and bustling maritime city even on a quiet day, today the city was alive with maritime traffic. Dozens of warships lined the quaysides, here to celebrate the Swedish Navy’s 500th anniversary on 7 June, and then take part in NATO exercises. Around them, tourist boats, pleasure crafts, and ferries raced around the city’s seven islands. And into this maelstrom of shipping we ventured in National Geographic Explorer’s Zodiacs. We explored the city from the sea, popping into the sheltered lakes behind the city’s parks to toast our arrival with champagne. We spent the evening ashore, taking advantage of our own Zodiac taxi fleet to venture into the old town of Gamla Stan, which got us in the mood for tomorrow’s activities.

Photo caption and photographer: Vaxholm Fortress. Photo by Stephen Fisher