Skagen, Denmark and Marstrand, Sweden

Yesterday's rain was the first we have seen for a fortnight, and it came complete with Thor's signature, thunder and lightning. But by the time we welcomed our new guests on board the good ship National Geographic Endeavour, the mackerel sky had cleared to a fresh Baltic blue. We left Copenhagen at 6pm, steaming north up the Øresund, past the turrets of Elsinore castle and out into the Kattegat. It was a fine sunset.

By early morning we were at the northern tip of Jutland, anchoring off Skagen, the most important fishing harbour in Denmark. Straight after breakfast we ran our Zodiacs into the sheltered harbour, past small fishing smacks and mighty trawlers, and set out to explore the area. North of the town, the peninsula tapers away to a wilderness of scrub, marsh and dunes, terminating in a fine tongue of blonde sand, licked by the sea on both sides. This promontory rose up from the seabed when the Scandinavian ice-sheet retreated 1000 years ago. Skagen gets its name from this feature, which means "appendix" in Danish, an apt title, for the sea is adding more sand constantly where the tides of the Baltic and the North Sea clash. To reach it, we took a tractor-drawn carriage called a Sandworm (picture), out through the dunes to the northernmost tip of Denmark, the Grenen. The combination of sun, sea and sand was too good an opportunity to miss: we cast off shoes and socks and went into holiday mode, wading out onto the wavewashed spit until we could stand with one foot in either sea, like Norse giants. After beachcombing along the strand line for razorshells and jellyfish, we climbed through wild rose bushes to a viewpoint and looked south to the tall lighthouse; beyond it our little blue ship rode gracefully at anchor. We could see the high dunes, which in the 16th century marched inland to engulf the original fishing village; today only the church tower is visible above the shifting sand. We finished at the museum dedicated to the 19th century artists of the Skagen school, a group of inspired painters who came to capture the unique quality of light and landscape here. They lived among the fishing families, which launched sailboats out through the surf to catch herring and cod here in the 1890s. The superb collection of oil paintings is like a time capsule, vividly bringing to life the treats, trials and tragedies of the close-knit community, which lived here a century ago.

Once back on board, the ship sailed due east to Marstrand on the Swedish coast. Here we went ashore at a quayside once swarming with herring fleets. The Marstrand flag is blue with a ring of 3 silver herrings to commemorate the fish, which made the town rich. Today it swarms with yachts and cruisers and the main catch is tourists, which shoal here in summer. We climbed the steep streets past beautiful gardens to reach the massive Carlsden castle, which dominates the town. Once through castle gates, down dark passageways and up spiral tower steps, we found ourselves out in the sunshine again, gazing down from the battlements to the rock terraces from which the castle walls were hewn, and out across a sea studded with scudding sails. On a clear night the lighthouse of Skagen can be seen winking on the horizon, 20 miles away to the west, in the land where the sandworm roams.