A submarine below the layer gains concealment but also loses contact quality and must maneuver carefully to attack. The layer is irregular, changes with conditions, and cannot be treated as a solid acoustic wall. A boat trying to fire and slip beneath it must do so quietly before the weapon activates and the escort begins an active search. Surface ships can measure the water column and lower dipping or towed sensors through the same layer, making ASW a positional contest in which both sides anticipate several moves rather than relying on a single technical trick.
Chapter · 1:56:20-2:05:00
Thermal layers complicate ASW but do not make submarines invisible
Thermal layers hinder sonar in both directions, while dipping and towed sensors let surface forces probe beneath them.