Chartplotter/fishfinder combos for serious anglers, Gen2 HDS units are faster than ever with lightning-fast chart updates and real-time StructureMap™ capability, which overlays StructureScan™ sonar imaging on top of nautical charts, for a comprehensive view of your location and finned quarry below. USA Insight Cartography gives you inland and coastal mapping-including the Great Lakes with detailed shorelines and depth contours, plus Fishing HotSpots data for more than 500 U.S. lakes-a $400 value, built-in! Contour shading offers stunning life-like perspectives of bottom structure and topography. FlyWheel™ scroll dial and command soft keys give you quicker, easier control and fine-tuning of fishfinding and navigational features. 16-channel GPS furnishes faster time-to-signal lock and precision position.