PrefaceCongratulations on choosing one of the most advanced marine navigation systems available! TheGarmin GPSMAP 172/172C models utilize the proven performance of Garmin GPS and full-featured map-ping to create an unsurpassed marine navigation chartplotter.This manual covers instructions for the GPSMAP 172 and GPSMAP 172C (color). Unit operationand specifications will be the same on both models unless otheriwse specified. For GSD 20 sonar relatedoperations, refer to “GSD 20 Sounder Module with Garmin Chartplotters” (190-00241-03). To get themost out of your new navigation system, take the time to go through this owner’s manual and learn theoperating procedures for your unit. This manual is broken down into two parts for your convenience.Part One introduces you to the GPSMAP 172/172C and provides a Getting Started tour so that youmay become more familiar with the unit. This section provides you with a basic knowledge necessary touse the unit.Part Two is divided into sections that provide detailed references to the advanced features and opera-tions of the GPSMAP 172/172C. This allows you to concentrate on a specific topic quickly and look updetailed information about the GPSMAP 172/172C.Customer Service Product RegistrationHelp us better support you by completing our onlineregistration today! Connect to our Web site atwww.garmin.com/registration/.Use this area to record the serial number (8-digitnumber located on the back of the product name) incase your product name needs service. Keep the originalsales receipt, or a photocopy, in a safe place.Serial Number:___ ___ ___ ___ ___ ___ ___ __Contact GarminContact Garmin if you have any questions whileusing your product name. In the USA contact GarminProduct Support by phone: (913) 397-8200 or (800)800-1020, Monday–Friday, 8 AM–5 PM Central Time;or go to www.garmin.com/support/, and clickProduct Support.In Europe, contact Garmin (Europe) Ltd. at+44 (0) 870.8501241 (outside the UK) or0808 2380000 (within the UK).Software License AgreementBY USING THE GPSMAP 172/172C, YOU AGREE TO BE BOUND BY THE TERMS AND CONDI-TIONS OF THE FOLLOWING SOFTWARE LICENSE AGREEMENT. PLEASE READ THIS AGREEMENTCAREFULLY.Garmin grants you a limited license to use the software embedded in this device (the “Software”) inbinary executable form in the normal operation of the product. Title, ownership rights and intellectualproperty rights in and to the Software remain in Garmin.You acknowledge that the Software is the property of Garmin and is protected under the United Statesof America copyright laws and international copyright treaties. You further acknowledge that the structure,organization, and code of the Software are valuable trade secrets of Garmin and that the Software in sourcecode form remains a valuable trade secret of Garmin. You agree not to decompile, disassemble, modify,reverse assemble, reverse engineer, or reduce to human readable form the Software or any part thereof orcreate any derivative works based on the Software. You agree not to export or re-export the Software toany country in violation of the export control laws of the United States of America.IntroductionPreface/Registration/Software License Agreement