User manual GARMIN GPSMAP 238 SOUNDER

[. . . ] GPSMAP 188/188C/238 Sounder chartplotting receiver & depth-finder owner's manual and reference guide (GPSMAP 188C Shown) © Copyright 2003 Garmin Ltd. or its subsidiaries Garmin International, Inc. 1200 East 151st Street, Olathe, KS 66062, U. S. A. 913/397. 8200 or 800/800. 1020 Fax 913/397. 8282 Garmin (Europe) Ltd. [. . . ] To display the track on the Map and Highway pages, highlight the check box to the left of `Show on Map and Highway' and press ENTER. To view the track on the map, highlight `Review on Map' and press ENTER. Press QUIT to exit the Track Map window. Highlight `OK' and press ENTER to save the track. Reference TracBack Navigation Default Track name Total Distance Change color or style of track line Check this box to display track Total number of points To activate a TracBack using the NAV key: 1. Press the NAV key, then highlight the `Follow Track' option and press ENTER. Highlight the track you wish to follow and press ENTER. Choose either `Original', which will navigate you from the start to the end of your trip, or `Reverse', which will navigate you from the end to the start of your trip and press ENTER. Once a TracBack has been activated, the GPSMAP 188/188C/238 Sounder will take the track log currently stored in memory and divide it into segments called `legs'. Up to 254 temporary `turns' (BEGIN, TURN 1, TURN 2, TURN 3, . . . . , TURN X, END) will be created to mark the most significant features of the track log in order to duplicate your exact path as closely as possible. To get the most out of the TracBack feature, remember the following tips: · Always clear the track log at the point that you want to go back to (dock, etc. ). · The `Record Mode' option on the track log setup page must be set to `Fill' or `Wrap'. · There must be at least two track log points stored in memory to create a TracBack route. You must first save a track before using the `Follow Track' option. If there are no saved tracks, the message "There are no saved Tracks to follow" appears after you select `Follow Track. ' 55 Reference TracBack Navigation/ MOB: Man OverBoard · If the track log interval is set to the `Time' option, the route may not follow your exact path (keep the interval set to `resolution' for best performance). · If the receiver is turned off or satellite coverage is lost during your trip, the TracBack will draw a straight line between any point where coverage was lost and where it resumed. · If your track log's changes in distance and direction are too complex, 254 waypoints may not mark your path accurately. The receiver then assigns the 254 waypoints to the most significant points of your track, and simplifies segments with fewer changes in direction. 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. Use any of the Navigation Pages to guide you back to the MOB 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. [. . . ] With the GPSMAP 188/188C/238, active whiteline helps accentuate where strong signals are located, which make bottom type determination easier. The example to the right shows the bottom return with and without the whiteline activated. Structure is hard-- probably a rock or stump Structure is soft-- probably a mud pile Hard Bottom Whiteline Soft Bottom Whiteline Turned Off 114 Example 4. Thermoclines One of the unique features offered by Garmin is See-Thru technology. See-Thru technology allows the GPSMAP 188/188C/238 to "see" through thermoclines and helps locate fish where they live; and fish love thermoclines!A rough definition of a thermocline is a break in water where the water temperature changes faster than the water above it. [. . . ]