Pre-Loaded with UK and Ireland Cartography GPSMAP 557xs combination chartplotter/sounder allows for easy visibility- day or night. Whether it is flat- flush or swivel-mounted- it will be the focal point of your helm. It includes our hallmark user-friendly interface as well as UK and Ireland1 BlueChart g2 charting. Super-fast 10 Hz GPS/GLONASS With the integration of a 10Hz GPS/GLONASS receiver- the 557xs refreshes position and heading up to 10 times per second. It displays constant and fluid on-screen location and proves to be incredibly accurate when marking waypoints and navigating. Advanced Echo HD-ID Sonar In addition to the integrated receiver- GPSMAP 557xs also allows for sonar recording. This feature coordinates the timing of the sonar return in relation to the boat's position — so every one of the available 5-000 waypoints will be accurate and precise. It's an absolute must when locating and pinpointing the next hot fishing spot. With our Spread-Spectrum technology- you can see target separation and resolution at extraordinary depths- and dial into specific frequencies to target certain species of sport fish. Bottom contours are more visible- and signal noise can be suppressed at greater depths to provide a more timely interpretation of what's below for safer navigation and better fishing.