Abstract: An inexpensive acoustic beacon-type system suitable for the self-localization of one or more submergable secondary vehicles such as AUVs. A single beacon in a primary system periodically transmits an acoustic signal to the secondary vehicle. The acoustic signal is passively received by at least two receivers such as an AUV-mounted ultra-short baseline (USBL) array, which enables multiple vehicles to localize using just a single beacon. A controller (i) maintains time-synchronization with the primary system, (ii) develops a range estimate signal from measurements of received signals from at least two receivers and (iii) develops an azimuth-inclination estimation of likeliest angle-of-arrival of the primary signals, wherein the controller utilizes a plurality of coordinate frames to provide an estimate of secondary system location.