Garmin GPSMAP 3206 Owner's Manual

Also see for GPSMAP 3206 - Marine GPS Receiver: Installation instructions Install guide Installation instructions Important safety information Quick reference guide

Contents

Garmin GPSMAP 3206 Owner's Manual Manual pdf 84 page image

6 GPSMAP 3206/3210 Owner’s ManualusIng sonar > understandIng sonarsonarusInG sonarThis section covers the additional options for the GPSMAP 3206/3210 whenused with a GSD 20, GSD 21, or GSD 22 sounder module. Read the installationinstructions included with your sounder to install it.NOTE: You must have a GSD 20, GSD 21, or GSD 22 sounder moduleinstalled and connected to your GPSMAP 3206/3210 to use the sonar features.The following section provides a general overview of sonar and thethings you need to know to help you use the sonar functionality of yourGPSMAP 3306/3210.Understanding SonarThe transducer mounted on your vessel sends sound waves down into the waterin a cone shape, similar to a flashlight beam (covering a smaller circular area atthe top and angling out to a larger circular area at the bottom). These sound wavesreflect off of any object that they hit, and then the waves travel back up to thetransducer. These objects could be fish, branches, the bottom, or any other objectthat has a density that is different from the water. The transducer receives thesound wave information, and then sends the information to the GSD 20, GSD 21,or GSD 22 sounder module and then to the GPSMAP 3206/3210. TheGPSMAP 3206/3210 displays the information on the screen for you to see andinterpret. The type of transducer and the settings that you choose determine howthe information is displayed on the screen.Using Dual FrequencyDual frequency works best for deep water (for example, off-shore) applications.The 200 kHz frequency allows you access to great detail about what is underneathyour boat. The 50 kHz frequency provides less detailed information, butpenetrates to greater depths with the same power. You can choose either or bothfrequencies to get the information that you want. If you choose dual frequency,the transducer alternates between the 50 kHz and 200 kHz signals. This capabilityallows you to see the best picture available at any depth.Using Dual BeamDual beam works best for shallow water (for example, inland) applications.A dual beam transducer can transmit a narrow or a wide beam. The water areacovered by the transmitted sound waves is determined by the beam width of thetransducer and the water depth. The narrow beam provides crisp detail of what isunder your boat, and is very helpful if you are fishing in deeper water where thebeam covers more area (for example, at a 30-foot depth, the narrow beam coversthe area of about a 7-foot circle).WdeBeamNarrowBeam