30 GPSMAP 182/182C Owner’s ManualM AIN PAGES > M AP PAGEThe GPSMAP 182/182C’s system has a built-in worldwidedatabase to 20 mi, with more detailed coverage available throughthe use of the BlueChart or MapSource data. The GPSMAP182/182C displays cartography as long as there is chart informationavailable for the range you have selected. Map coverage conformsto the following conditions:• When the selected zoom range is covered by the internaldatabase, BlueChart, or MapSource data, cartography isdisplayed.• When the selected zoom range is covered by boththe internal database and BlueChart/MapSource data,cartography is displayed using the data with the bestresolution.• When the selected zoom range exceeds the resolution of thedata in use, an Overzoom warning appears below the scale.Map Page OptionsMany features of the GPSMAP 182/182C are menu driven. Eachmain page has an options menu, allowing you to customize thecorresponding page to your preferences and/or select specialfeatures that specifically relate to that page. The data window,located at the top of the main pages, provides a user-selectablelayout of various types of useful data. Each data field can beconfigured to display any one of several data options. The datawindow layout can be configured to display additional data fieldsand change the size of the data displayed.The Map Page provides access to functions and features relating tothe Map Page and layout options.To display and select the Map Page options:1. Press MENU.2. Use the ROCKER to highlight an option, and press ENTER.The available options are Full Screen Map/Show Data, ChangeNumbers, Measure Distance, Show Sonar (If equipped with anexternal Sonar Module, see the “Using Sonar” section onpages 78-91 for details on this feature,) Set Up Map and TurnDeclutter on/off. Following are details on using each of theseoptions.