Photographs taken during friendly port visits recorded more than visiting sailors and their hosts. Fuel storage, heavy wharves and deep battleship berths could later help planners identify targets and approaches. Moving those facilities required substantial money and construction, so photographs five or ten years old could still describe the essential layout. The investment in Portsmouth for the Queen Elizabeth-class carriers supplies a modern comparison: large warships need suitable supporting infrastructure, and that infrastructure is expensive to relocate.
Notable Point · 11:54-13:19
Peacetime port photographs retain intelligence value
Old photographs could remain useful because the deep berths and heavy facilities needed by capital ships changed slowly.