Abstract: A ranging and data taking system, useful as an acoustic sediment classification system. The system launches acoustic pulses into a water column above a sediment bed of interest (seafloor, riverbed, etc.) and records echoes from the pulses. The recorded echoes are transmitted to a processor, which uses the echoes to classify the sediment. Disposed between the hardware for data acquisition, and the processor, is S-RAM (static read only memory). This decouples data acquisition and data processing, which increases the speed of the system sufficiently that the system can display processed data, such as sediment contour plots, in virtual real time.