The best chance of surprise comes from sending the fleet through the Danish Straits at night and beginning landings around first light. Sparse local defenses might be overwhelmed before Germany identified the scale and purpose of the movement. High-powered German radio transmissions could then reveal that forces were mobilizing before Britain decoded their content. Identifying transmitting stations and the direction of traffic could help locate a response from Kiel or Wilhelmshaven. This traffic analysis differs from the codebreaking associated with Room 40. The claim that traffic-analysis material remained classified is part of the argument for its lasting intelligence value. In this scenario Jellicoe knows the likely departure points, so the German need to communicate reduces some of his uncertainty.
Chapter · 1:41:31-1:46:17
Night passage, surprise, and German radio traffic
A night passage could put troops ashore before Germany understood the target, while radio traffic analysis warned Jellicoe where and when the response was forming.