 A Terne III weapon system consists of a search & track sonar, a fire-control system and the rocket launchers, which can store six salvos of six rockets each.The rocket itself, is a depth charge with multiple fusing modes (preset time after water entry, proximity, or contact), which is propelled through the air by a solid-fueled rocket motor.When the sonar detects a target, the fire-control system can fire a rocket salvo to place a string of depth charges apart, perpendicular to the target's course.