Abstract: 1. In a homing torpedo, in combination: means for providing a target search hase of torpedo operation wherein said torpedo is controlled to change depth between predetermined search floor and search ceiling depths and simultaneously controlled to circle in azimuth, whereby to execute helical search action; means for switching, in response to target acquisition at any time during a search phase of torpedo operation, to a target pursuit phase of torpedo operation; and means for switching, in the event of and in response to target loss continuing for a predetermined period in a target pursuit phase, to a modified search phase of torpedo operation wherein said torpedo is initially controlled to execute circle search action while maintaining depth position at substantially that at which target loss occurred, for a predetermined period accommodating at least a complete azimuth circling turn, then controlled to revert to helical search action.

Abstract: 1.

Abstract: 1.

Abstract: Method and apparatus for reducing torpedo drag in which polymer drag redug material is carried by the torpedo in concentrated form, ambient water is ingested and mixed with the concentrated polymer to produce a seawater-polymer solution of predetermined concentration, and the solution is ejected from the torpedo nose to be swept rearwardly in intimate contact with the exterior surface of the torpedo under torpedo forward motion.