Garmin GPSMAP 178C Sounder 4.25-Inch Waterproof Marine GPS and Chartplotter With Sounder (Internal Antenna) Fully integrated marine depth sounder with GPS navigation, chartplotting, and powerful sonar Built-in worldwide marine basemap compatible with MapSource BlueChart cartography State-of-the-art 200 MHz processor; crisp 256-color, 4.5-inch diagonal LCD display See-Thru technology separates fish from thermoclines and structures for added detail 10,000 active track points, measures 6.3 x 4.9 x 2.8 inches (W x H x D); 1-year warranty