The unmatched accuracy and detail of Humminbird LakeMaster give you a serious edge. Patented features include the ability to select and highlight a specific Depth range, the option to shade shallow water ranging from zero to 30 feet, and the power to synchronize Depth Chart contours and shorelines with the current water levels of lakes, reservoirs and rivers. With these exclusive features and more, you'll have everything you need to make your time on the water more productive. Humminbird LakeMaster great plains, version 6 combines many of the best fishing waters for Iowa, Illinois, Kansas, Missouri and Nebraska, all on one map card. Version 6 also brings the groundbreaking technology of follow the contour to your fingertips. When combined with a compatible i-pilot link system, your map card allows your boat to automatically follow a path directly on or offset from any contour, so you can focus on fishing. Version 6 contains 160 new or updated lakes from the previous version, and now has over 500 total lakes with contours, of which more than 400 are now high-definition lakes including:- table rock, Mo - lake of the Ozarks, Mo - three mile, IA - twelve mile, IA - pleasant creek, IA - Cedar, IL - East loon, IL - El Dorado, KS - banner, KS - Bull shoals, Mo- mcconaughy, NE- plus many more! The map card also features other great fishing waters, including: - Keith Sibelius, KS- Wilson, KS - Smithville, Mo - Truman reservoir, Mo - Red rock, IA - Illinois River pools - Mississippi River additionally, the card has outstanding coverage on lake Michigan: - all of lake Michigan (5 ft. and 10 ft. Contours)- green Bay (3 ft. Contours) - big Bay De Noc (3 ft. Contours) - little Bay De Noc (3 ft. Contours) - sturgeon Bay (3 ft. Contours) - little Traverse Bay - grand Traverse Bay.