Abstract: An accentuator circuit for underwater acoustical devices having a transmitter circuit and a receiver circuit each connected to underwater unit means which interchanges electrical signals and acoustical wave fronts in the water. The receiver circuit provides receiver outputs in accordance with distances traversed by the reflected wave fronts. The wave fronts reflecting from the bottom of the body of water produce a series of receiver outputs within an interval of time resulting in a bottom smear in the display in the prior art units. The invention includes an accentuator circuit connected to the receiver output comprising a series connected diode which substantially eliminates the bottom smear encountered by the prior art units enabling the resolution of an object which occurs within the aforesaid bottom smear. Consequently, objects such as fish which are located in close proximity to the bottom of the body of water can be readily detected.