GARMIN GPSMAP 178C Sounder Chartplotter w/Build In GPS Antenna Marine NavigatorGARMIN GPSMAP 178C SOUNDER FISHFINDER SONAR chartplotter GPS w Mount Cable Marine Navigator In perfect working condition with warranty. With build in GPS antenna ******* Own the lake with the GPSMAP 172C and its counterpart, the GPSMAP 178C Sounder. With a bright, sunlight readable color display and worldwide marine basemap, the 172C is ready to chart your next marine adventure. Chart Your Course The GPSMAP 172C features a built in worldwide marine