At low tide, the mudflats on the south side of Spiekeroog expose a vast tidal landscape stretching towards the mainland. Guided walks — Wattwanderungen — cross the sea floor between islands and from the mainland to the island, following routes through channels and mudbanks that are passable only at specific states of the tide. Local guides know which crossings are safe and provide rubber boots for the experience.
The walks cover terrain that appears featureless from a distance but reveals extraordinary detail up close: lugworm casts, cockle beds, crab holes, and channels scoured by the tidal currents. Grey seals haul out on the sandbanks within view. The eastern end of the island is permanently closed to visitors to protect nesting birds, but guided walks in the western mudflats offer excellent birdwatching throughout the year.