Garmin 010-01101-01 GPSMAP 721xs without Transducer Includes Worldwide Basemap Super-fast 10 Hz GPS/GLONASS Advanced Sonar Support- Built-in support for a wide selection of Garmin transducers, including 50/200 kHz, 77/200 kHz, DownVu and SideVu scanning sonar and CHIRP. In addition, it will also support Minn Kota and Motor Guide trolling motor transducers. Add the Clearest Scanning Images on the Water - Add the optional GCV 10 black box sonar to enjoy Garmin DownVu and SideVu scanning sonar with the clearest scanning sonar images on the water. Special Features for Sailing - Supported sailing features include lay lines, enhanced wind rose, heading and course-over-ground lines, true wind data fields and tide/current/time slider. Get Your Apple Device Onboard with Blue Chart Mobile