Abstract: A fish finder system, comprising a sonar gadget, which communicates with a display device via digital wireless communication. The system contains a software product, which runs both on the sonar gadget and the display device, wherein the gadget part of the software is preferably adapted to run on an embedded microcontroller system and the user display device part of the software is preferably a downloadable application adapted to run on portable communication devices, such as smart phones, tablet computers, laptops or the like. Said display device part of the software is adapted not only to visualize the obstacles with indication of depth, size and movement, but also provide additional functionality, such as access to a camera device, digital maps and GPS, social network accounts, weather information and forecast, calendar with notes, information on moon phases and other kinds of information found on the Internet. Both software parts allow update functionality.