Garmin echoMAP CHIRP 54dv without transducer CLEARV SCANNING SONAR - Shows you more of what is in the water around your boat. This high-frequency sonar gives near-photographic images with detailed representations of objects, structure and fish. CHIRP SONAR - CHIRP sends a continuous sweep of frequencies which provides a wider range of information. CHIRP sonar is able to create crisper fish arches with better target separation. BUILT-IN MAPS AND CHARTS - Available with either U.S. BlueChart g2 charts, U.S. LakeV HD maps or Canada LakeV HD maps. Includes Quickdraw Contours custom HD map creation software CLEAR SCANNING SONAR - The cv series comes with built-in 500 W CHIRP traditional sonar and CHIRP ClearV scanning sonar. The sv series offers all of the same features plus CHIRP SideV scanning sonar. BEST-IN-CLASS INTERNAL 5 Hz GPS - Internal 5 Hz GPS updates position and heading 5 times per second to make marking and returning accurately to waypoints easier.