When operational evidence outruns the surviving paperwork

The 10th Destroyer Flotilla's station keeping in fog is the strongest reason offered for believing crews adapted their radars to PPI. The ships held their positions without colliding, despite darkness and the absence of lights that would have disclosed their presence. Good eyesight and ordinary station keeping are rejected as sufficient explanations for that performance in fog. Radar operation is therefore treated as the only explanation that fits the available accounts. The conclusion remains more definite in the spoken argument than in the published wording because no direct reference confirms the alteration.