Provided are a sonar system and transducer assembly for producing a 3D image of an underwater environment. The sonar system may include a housing having a transmit transducer that may transmit sonar pulses into the water. The system may include at least one sidescan transducer array in the housing that receives first and second sonar returns with first and second transducer elements and converts the first and second returns into first and second sonar return data. The first sidescan element may also transmit second sonar pulses, and at least one of the sidescan elements may receive the second sonar pulses to generate sidescan sonar return data. A sonar signal processor may then generate a 3D mesh data and sidescan image data and generate a 3D image data based on the 3D mesh data and sidescan image data. An associated method of using the sonar system is also provided.