Heligoland and the approach to Wilhelmshaven

Wilhelmshaven was a shallower target than Taranto, with access depending heavily on the Jade channel. Heligoland sat across the approaches to both Wilhelmshaven and the Kiel Canal, making it a strategic obstacle rather than a minor coastal outpost. Britain acquired the island from Denmark in 1807 and transferred it to Germany in 1890. Keeping the position would have required concrete, guns, and extensive digging, but it could have helped Britain obstruct ships leaving either German approach. In this interpretation, the transfer was a strategic mistake: Germany later turned Heligoland into a fortified naval base used by major warships. Any British harbour-strike plan now had to account for a defended island controlling the route to its target. The vast conventional explosion used to demolish the base after the Second World War gives a sense of how substantial the fortifications had become.