Depth Gauges with Transom Mount Transducer 2 to 590 ft [0.6 to 180 m], or 0.3 to 100 fathoms* Too deep and too shallow alarms Optional external alarms (sound or light) 12 vDC, up to 100 mAmp Surface clutter filter (3 levels) for greater accuracy Choice of units: metres, feet or fathoms Keel offset