Humminbird 587ci HD Waterproof Marine GPS and Chartplotter with SounderThe Humminbird 587ci HD / Fish-finder Combo comes with high definition color on a 4.5" 640 by 480 display. It has DualBeam Sonar with SwitchFire, 2400 watts PtP. The narrow, 20 degree sonar beam 200 kHz allows excellent detail of the bottom and structure directly under the craft. The wider, 60 degree sonar beam @ 83 kHz searches for fish and structure in the area surrounding the craft, though it can't see the same detail as the narrow beam. The coverage area you see on the screen is equal to your depth. The depth capability of this unit is 1000 ft.

the 587ci comes with a fifty channel internal GPS with built-in antenna and preloaded Uni-Map that covers the continental US shoreline, inland lakes, and rivers with a resolution of thirty meters per pixel. It has a single  slot for expansion of memory. It has custom view selections, a mounting system that is a quick disconnect type and the transducer is a tramsom mount. The dimensions are 6.9" Wide, by 7.5" Height, by 4.5" depth.