A forward base for air and anti-submarine warfare

Helgoland would be an unusually useful forward base for Royal Naval Air Service fighters, anti-submarine aircraft, and listening equipment. Fighters could intercept Zeppelin raids over or near the German coast instead of waiting for them above Britain. Hydrophones and aircraft could also watch the narrow routes used by U-boats heading into the wider North Sea. Because German submarines and airships would have to pass close to these detection and interception forces, leaving the island alone would steadily erode Germany's offensive options and strengthen the incentive to attack early.