Blenheim, France I, and ambiguous mooring lights

The unusually long five-masted France I displayed mooring lights at both bow and stern while anchored off Dungeness. Although large vessels informally used that arrangement, the formal rule required only a single bow light. Blenheim's watch therefore interpreted the two lights as separate anchored ships and steered for what appeared to be the safe gap between them. Bells, flares, and a foghorn from France I prompted a last-moment turn that reduced the collision to a glancing blow rather than a strike near the central mast. The British court declined to assign Blenheim responsibility because her watch had followed the written rules, a conclusion that understandably angered French and wider maritime opinion. The accident demonstrates how an unofficial safety convention can create danger when it is not shared, standardized, or supported by modern identification tools.