User manual GARMIN GPSMAP 820

[. . . ] Garmin hereby grants permission to download a single copy of this manual and of any revision of this manual onto a hard drive or other electronic storage medium to be viewed and to print one copy of this manual or any revision hereto, provided that such electronic or printed copy of this manual or revision must contain the complete text of this copyright notice and provided further that any unauthorized commercial distribution of this manual or any revision hereto is strictly prohibited. Garmin reserves the right to change or improve its products and to make changes in the content without obligation to notify any person or organization of such changes. Visit the Garmin web site (www. garmin. com) for current updates and supplemental information concerning the use and operation of this and other Garmin products. GARMIN®, AutoLocate®, GPSMAP®, See-Thru®, DCG (Depth Control Gain)®, MapSource®, BlueChart®, and TracBack® are registered trademarks of Garmin Ltd. [. . . ] With the `Go To' button highlighted, press ENTER to begin navigation. Choose a waypoint from either the `User' or `Nearest' tab list. To stop navigation: 1. Use the ARROW KEYPAD to highlight `Stop Navigation' and press ENTER. Selecting a `Go To' Graphically A graphical `Go To' may be used to select one of three items from the map display: an existing waypoint, an on-screen map item (roads, rivers, cities, navaids, etc. ), or a new map point (non-map item). If you select a map item as the `Go To' destination, the GPSMAP 188/188C/238 Sounder will automatically use the name of the map item, but the point will not be stored in the waypoint list (see page 45 for creating waypoints using map items). If you select a new map point (non-map item) as the `Go To' destination, the GPSMAP 188/188C/238 Sounder automatically creates or moves a waypoint named `MAP' at the cursor position. The waypoint or map item name will automatically appear when highlighted and NAV is pressed. 53 Reference Going to a Destination/ TracBack Navigation To activate an existing waypoint or map item as a `Go To' from the map display: 1. Use the ARROW KEYPAD to highlight the waypoint or map item on the screen and press NAV. With `Go To <waypoint name>', press ENTER. To activate a new map point (non-map item) as a `Go To' from the map display: 1. Use the ARROW KEYPAD to move the arrow cursor to the desired position and press NAV. With `Go To MAP Point' highlighted, press ENTER. `Go To MAP Point' allows you to navigate to a spot on the map that is not a waypoint or map item. To stop navigation: 1. Use the ARROW KEYPAD to highlight `Stop Navigation' and press ENTER. TracBack Navigation (Follow Track) The TracBack function allows you to retrace your path using the track log automatically stored in the receiver's memory, which eliminates the need to store waypoints along the way. TracBack routes are created by reducing your track log into a route of up to 50 turns and activating an inverted route along those points. Once activated, a TracBack route leads you back to the oldest stored track log point, so it's a good idea to clear the existing track log before you start your current trip. To clear the track log and define a starting point for a TracBack route: 1. Press the NAV key, highlight `Stop Navigation' and press ENTER. The MOB function allows you to quickly activate a course back to a location. For more information on setting up the Track options and saved tracks, see pages 75-76. MOB Key The GPSMAP 188/188C/238 Sounder's Man OverBoard function (MOB) lets you simultaneously mark and set a course to a position for quick response to emergency situations. To activate the MOB function: 1. Press ENTER to confirm and begin navigating to the MOB position. Highlight `Stop Navigation' and press ENTER to stop navigating. Once a MOB has been activated, a `MOB' waypoint with an international MOB symbol is created and the unit is set on an active navigation to that point. The MOB waypoint is stored in the waypoint list and may be deleted like any other waypoint (see page 50). To stop navigation to the MOB position: 1. Press the NAV key, highlight `Stop Navigation' and press ENTER. 56 Creating a Route Reference Creating a Route The last way to navigate to a destination is to create a user-defined route. The Garmin GPSMAP 188/188C/238 Sounder lets you create and store up to 50 reversible routes (numbered 1-50), with up to 254 waypoints each. The first way is by selecting points from the Map Page, allowing you to see each route graphically on-screen as you create the route. The second way is to select waypoints from the Find menu, allowing you to see a list of the route points as you create the route. To create a route, start by accessing the Main Menu. To create a route graphically: 1. Or, highlight the first available blank slot in the Route List and press ENTER. To add an existing waypoint or map item to the route, use the ARROW KEYPAD to highlight the desired waypoint or map item on screen and press ENTER. To add a new waypoint to the route, use the map cursor to select the desired map position and press ENTER. [. . . ] Fish returns from the wide and narrow beams appears differently on the display. The wide beam tends to show longer fish returns than the narrow beam. 200kHz - 10° Cone Angle 72" coverage at 30' 50kHz - 40° Cone Angle 20' coverage at 30' Wide Cone Angle Narrow Cone Angle 112 Understanding the Graph It is important to understand that the unit does not display a 3-D representation of the underwater environment. The unit can display multiple things at the same time, but cannot determine where the return originated ­ only when it was received. Examples 1 and 2 provide a look at the underwater world from a top view, and illustrate how these views would be displayed on the graph. [. . . ]