Working like an underwater radar, the Probe scans a moving beam vertically from just below the surface to directly beneath your boat to show 'live action' views of changing bottom contours, structure obstructions and schools of fish ahead of your boat. In addition, the Probe operates with a full function downward looking mode for conventional fishfinding action. Looking 1200 feet ahead of your bow and down to 640' below the keel, the Probe gives you a clear view of the entire water column ahead of and below your boat. The front panel knob control allows optimum adjustment of the forward beam direction and width with a unique alarm that can be set to warn of upcoming bottom changes. Completely waterproof. High resolution backlit LCD provides clear, crisp echoes from the 300-watt RMS transmitter. Operating at 200kHz, the downward looking fishfinder can also be split screened to show forward looking data, track plot data and navigational digital data. 'Power Off' memory remembers all of your settings even during power off. The eight-channel phased array forward looking mode scans a 12? beam area from the surface to below your boat and outwards 1200 feet. Optional speed/temp sensors available. Size: 7.5'' x 5.5'' x 3.5''.