The paper discusses a solution for platform location in underwater acoustics. The work is relevant to several fields such as the passive detection and tracking of underwater mobiles, the navigation of platforms relative to bottom‐moored sources, the coherent synthesis of acoustic apertures, etc. This paper proposes the design of efficient algorithms that recover position and dynamics information by processing the radiated signature of nonfixed sources. There are conflicting requirements: Global location, e.g., the global recovery of the source/receiver separation, and minimization of the associated computational effort. A compromise is a receiver structure, herein referred to as the hybrid algorithm, that exhibits two basic modes of behavior. In the acquisition mode, the hybrid algorithm is globally observable, but nonrecursive. In the tracking mode, the hybrid algorithm, being recursive, is locally observable. The irregularities of the source path impose a maximum time for the acquisition mode, while the tracking mode is time‐limited by the unbounded time behavior of the error variance at the output of the recursive algorithm. For the underwater problem, the paper discusses compromises between these time constraints, as well as the consequences on the error performance of operating the acquisition and tracking modes for longer or shorter periods. It establishes strategies to follow in practical acoustic problems, quantifying the relation between the hybrid algorithm behavior and the parameters characterizing the geometry and the statistical noise environment.