AdvanSea Combo C.56. 5.6" GPS Combo, Chart Plotter / Fishfinder. Built in Antenna. All-in-one navigator: combines a high resolution VGA GPS chartplotter with powerful dual frequency sonar. This is not just another brand in electronics, this is Advancing Navigation Technology. The new advanSea program has been inspired by the valuable feedback gained from listening to yachtsmen for many years. Advansea have combined this experience with the latest LCD and GPS engineering technology, to provide boaters with navigation essentials. AdvanSea offers enhanced ergonomics, user-friendly intuitive software, easy installation and state-of-the-art navigational features. Whether you are looking for a basic single function integrated program, advanSea, the name to go to sea with... Combo C.56 is supplied with the Airmar P58 tri-function transom transducer (depth, speed, temperature) or adaptor cable to select your optional through or in-hull transducers.