SONAR MAPPING SYSTEM

A sonar mapping system that includes a sonar transducer assembly configured for mounting on a watercraft, and a display configured to show a topographical chart of a body of water. The sonar mapping system further includes a processor coupled to the sonar transducer assembly and display. The processor is configured to create the topographical chart in real time, and to update the topographical chart in real time, based on sonar data provided by the sonar transducer assembly. The processor is also configured to render the created or updated topographical chart on the display. The sonar mapping system has memory accessible by the processor and configured to store the topographical chart rendered by the processor, and to store the sonar data provided by the sonar transducer assembly.