Techniques are disclosed for systems and methods to provide casting guidance for users of mobile structures, including watercraft. A casting guidance system includes a sonar transducer assembly and a logic device configured to communicate with the sonar transducer assembly. The sonar transducer assembly is adapted to be mounted to a mobile structure and placed in a body of water. The logic device is configured to identify one or more underwater targets in sonar data received from the sonar transducer assembly, determine casting guidance parameters corresponding to the one or more identified underwater targets, and generate at least one casting guidance identifier based, at least in part, on the determined casting guidance parameters. Subsequent user input, the sonar data, and/or the casting guidance parameters may be used to adjust a steering actuator, a propulsion system thrust, and/or other operational systems of the mobile structure.