By Richard S. Wilson
March 10, 2001  Release 1
Revised April 22, 2001  Release 2

Revised December 6, 2001  Release 3

On November 30, 2001 the software for the GPSMap 162 was upgraded to version 3.03.  See the addendum at the end of this review for the changes.


This is a review of the Garmin GPSMap162 (S/W ver. 2.60) with Fishing Hot Spots maps (S/W ver. 1.27) loaded through MapSource (S/W ver. 3.06 Beta).  The GPSMap 162 is a 12 channel marine unit which will include WAAS (Wide Area Augmentation System) when using S/W ver. 2.60 or higher (this can be downloaded at no charge from the Garmin Web Site).  It is programmed with an internal base map, Americas 2.0.  This map shows the land masses and some of the major cities around the world, and major highways and waterways in the U.S.  Garmin MapSource maps can be programmed into it from a CD-ROM for areas of the U.S., Canada, or the world.  The list of maps and the information about them is too vast to be included as part of this review, but descriptions and details of these various CD’s and the MapSource program can be found on the Garmin Web site HERE.   These maps make the GPSMap 162 a versatile navigation tool that can be tailored to any part of the world.  Although there are numerous Fishing Hot Spots maps for the U.S., the one used in this review is Old Hickory Lake, impounded by Old hickory Dam on the Cumberland River.  It is located just northeast of Nashville, Tennessee and is a navigable federal waterway that has access to the ocean through a series of locks and dams on the Cumberland, Ohio, and Mississippi Rivers.  Street prices of the G-162 with external antenna are around US$400.  The model pictured above with the internal antenna is about US$360.  Click HERE for latest prices.


This unit will NOT accept the Garmin G-Charts, detailed navigation charts for off-shore or inland waterways.


The GPSMap 162 is designed to operate from the boat electrical system (10 – 40 VDC), but comes with a wiring harness containing the G-162 fuse on one end and a fuse and unterminated wires on the other.  An optional 120VAC power supply with com port adapter, and connector for the GPS is also available.  This AC adapter is convenient  when setting up the unit with downloadable maps from a desktop PC, although the standard boat power cable also includes the wires that can be used to connect to a laptop PC in the boat with the addition of a suitable DE9 connector.

The GPSMap 162 kit has an external amplified antenna that is about the size of a baseball with a 30 ft. cable that connects to the back of the unit.  This is usually long enough for most applications, but extension cables are available.  The unit is also available in an internal antenna model.  The external antenna model can be easily converted to an internal antenna with an optional bail mount that replaces the mount on the back of the unit.  The new mount plugs in to the antenna connection when it is attached, so there is no wiring required.  The G-162 antenna port provides power for standard Garmin amplified GPS antennas and it also works with standard unamplified GPS antennas on a short extension cable.

This unit is WAAS compatible after loading S/W ver. 2.60 which gives results similar to connecting a DGPS receiver to the unit for increased accuracy.   "In the clear" static accuracy in one series of tests in Georgia provided the data shown HERE.  The GPSMap 162 comes in a black case about 6 inches wide and about 4 ¾ inches high.  A cover is provided for the display when not in use.   The display screen is approximately 3 ½ inches square.  The controls include a CURSOR MOVEMENT button, ZOOM OUT, ZOOM IN, PAGE, QUIT, ENTER/MARK, MENU, NAV/MOB, and POWER/LIGHT.  The use of these buttons is described later.  It has a swivel bracket for surface mounting or can be flush mounted into a panel or the boat's console.

It has five screen displays, called pages, that are used for navigation.  The pages are sequenced forward or backward by using the PAGE and QUIT keys.  A feature on the Main Menu allows the user to delete any of these pages from the normal viewing sequence if he seldom uses them.  The following descriptions of the pages are as they appear in the default view. The pages can be tailored to your personal preferences, with no data, perhaps 1, 2, or 3 lines of data, small, medium, large, and sometimes huge print, data type, and position on the page.

1.  The Status Page (or GPS Page) is where the unit starts while acquiring the satellites.  This shows a sky view of the satellites positions, vertical bars showing the status of up to 12 satellites: no data, located and obtaining data, or locked in and ready for use.  The page has data cells giving the date and time, estimated accuracy, DOP, DGPS status, and geographic location.  When 3 satellites are locked in, the unit establishes the location in 2D navigation and switches to the Map Page.  Data from a fourth satellite puts it in the 3D mode which includes altitude.  With WAAS enabled the status bars will include the letter “D” to indicate that the signal from that satellite is being corrected.

2.  The Map Page is just that: It shows the map with the present location in the center indicated by a small arrow which points in the direction of travel when moving.  The map orientation can be changed so that the route is up, or the track is up.  The scale may be changed by using the Zoom In or Zoom Out buttons from ½ inch = 800 miles (The whole US, Canada and part of South America) to ½ inch = 120 ft.  The page has data cells showing the speed, distance to the next destination, and an arrow indicating the direction to steer to get on course.  The map shows waypoints, tracks, routes, and any details that are included on the map currently in use for that area.  The map shading can be changed from water mode to land mode which reverses the colors (black, white, and shades of gray) to improve visibility of the map.


                            Land Mode                                                            Water Mode

3.  The Compass Page has a compass with an arrow in the center.  The orientation of the compass has the current heading at the top, and the arrow points in the direction to steer to the next destination.  The arrow is not present if the unit is not in the navigating mode.  The page has 3 data cells which show speed, distance to next destination, and time to next destination.  It also has a text bar Navigating to: Next Destination.

4.  When in the navigation mode, the Highway Page is a graphical representation of an artificial highway starting at the bottom and extending up, disappearing into the distance.  The waypoints appear on this highway and the highway turns to join them together.  The present location is the bottom of the page.  The scale of the page can be changed to see more or fewer waypoints, or for clarification depending on the distance between waypoints.  There are 6 data cells giving speed, distance to next destination, direction to steer to the next destination, distance off course (track), time to next destination, and current track.  It also has a text bar Navigating to: Next Destination.

5.  The Active Route Page is a text page that shows the name of the active route being followed, along with the waypoints on that route.  It shows the distance from the present position to each of the waypoints and the course to steer between each waypoint.  These are constantly updated as the boat moves.

A simulator mode allows you to follow a route and view the pages as they would appear in actual navigation.  In the Highway Page you can “steer” the boat and change speed.  You can sequence through the pages  to see the results when you navigate, get off course or miss a waypoint.

The variable backlighting and contrast features ensure that it is easy to see in any kind of light.  These are controlled with a momentary press of the POWER/LIGHT button and CURSOR MOVEMENT rocker switch.

The NAV/MOB button brings up a menu that allows selection of the type of navigation, and then the destination for navigation.  Pressing this button twice, then ENTER/MARK creates a waypoint named MOB (Man Overboard) and sets up navigation to that point.

The ENTER/MARK button is used to select an item on a menu, and also set a new waypoint on the map.

The MENU button will bring up a menu on each page that allows the page to be re-configured or perform other tasks relevant to that page.  Pressing the MENU button twice brings up the Main Menu.  This is where the waypoints and routes can be developed and edited, trip data can be reset, time format and zone can be established, and pages can be turned on or off.  Here the orientation of the Map Page can be changed, along with the size of the text and details on the map, and the various downloaded maps in memory can be turned off and on as well as the internal base map.

The map page includes an accuracy circle around the pointer, the radius of which is based on EPE, DOP, and  map quality.  Even with all the possible errors, your actual position will supposedly be somewhere in this circle.  The circle can be turned off in the Main Menu, but in close locations it will allow you to make adjustments to your position to make sure you are in a safe area.

There is a tide page included in the Main Menu showing the times and heights of the tide, both graphically and in printed values.  The date can be changed to allow viewing of tides on future dates.  (See addendum at the end of this review for changes in the tide feature of the unit.)  A celestial page shows the relative position of the moon and sun from your location, phase of the moon, time of sunrise, sunset, moonrise, and moonset.  Again, the date can be changed to get a future days information, and the location can be changed to get data for that location.

There are a number of audible alarms that can be set, turned on and off.  The unit can be used as an ordinary alarm clock, if desired.  There is an off course alarm that will keep you on your route.  An anchor drag alarm can be set for a distance change of 0.01 to 10.00 miles, and will sound if the boat drifts that far from its original location.  An arrival alarm can be set to sound when you either reach a pre-set distance, or a pre-set time from your destination, based on your current speed.

The GPSMap 162 will store up to 500 waypoints and 20 routes of 30 waypoints each.  The routes can be reversed as needed.  The waypoint names can be up to 10 alphanumeric characters which makes them easily recognizable.  They can be identified by any one of 38 icons which is then placed on the map.  The unit records the actual track of the boat and the TracBack feature allows you to convert this into a route that will take you back along the same track to your starting position.

The Acquisition times posted in the manual are: warm start, 15 seconds, cold start, 45 seconds, auto-locate, 5 minutes.  This unit bettered  those specifications, with a warm start as low as 8 seconds, cold start after a 2000 mile relocation as low as 17 seconds.  Position accuracy specification  is 15 meters (49 ft.) and can be 1 to 5 meters (3 to 15 ft.) with an optional DGPS receiver.  With WAAS enabled the unit showed an accuracy as low as  2 meters (about 6 ft.).  See sample of position measurements made at a fixed location and out in the clear away from trees, etc. HERE.

The MapSource program is run on a PC with a CD-ROM drive.  Using the available maps from Garmin you can see details of the area selected, create waypoints and routes, measure distances, and find locations.  These maps and their associated features can then be loaded into the GPSMap 162.  The MapSource program is very easy to operate.  It has a series of icons on the tool bar that are enabled by clicking on them.  They include zoom in and zoom out, a zoom tool that will re-center the map and zoom in on that point, a hand tool that lets you grab the map and move it around on the screen, a selection tool that when pointed to an object brings up a name and description of the object and is also used to select items for deletion, a waypoint tool which creates a waypoint by clicking anywhere on the map, a route tool that creates a route by clicking on waypoints in sequence,  map tool that can be used to locate the individual maps in a map set and add or delete them from the set, and a distance and bearing tool that is used to determine the distance between points on the map, and get a bearing to follow.  A text area with tabs lists the maps, waypoints, routes, and tracks in memory.  These can be selected for editing and deleting and the map is then updated.  With the GPS connected to the computer serial port the map is downloaded with one click on the download icon.  Likewise maps (actually the names of map sections that are recognized by MapSource to allow selection of the proper map from the CDROM)  can be uploaded from the GPS with one click of the upload icon.

The Fishing Hot Spots map of Old Hickory Lake shows the navigation lights, marinas, boat ramps, and roads near the water.  The details of the water area include channel markers and buoys, river mile markers, bottom contour lines, water depth, submerged roads and structures, and of course, the "hot" fishing areas.  The old river bed and tributary stream beds are marked so that you can follow the deepest channels to a location.  The navigation markers are actually red and green, but being a black and white screen, the map shows them as G or R to indicate color.  The fishing spots are shaded areas and indicate the areas most likely to have good fishing.  By moving the cursor in the Map Page over an item marked on the map and pressing enter you can see a narrative about that item.  For instance, selecting the river bed will tell the name of the lake, how big, how deep, when it was formed, general information about it, and its history.  Selecting a park will list the facilities available such as water, boat ramp, groceries, fuel, and many other things.  Selecting a marina will list the facilities available there.  Selecting a fishing area will tell the best seasons, type of fish, water temperature at certain times of the year, and other fishing information.



Although the MapSource CD contains many maps, an unlock code must be entered to view the several map regions.  Installing the MapSource CD with the GPS connected to the serial port will allow you to update the GPS software if necessary.  MapSource then instructs you how to access  the Garmin Web Site, and using a code that came with the disk and the GPS serial number, you will receive an unlock code.  Entering that code into the MapSource program then brings up the detailed map.  I then created a number of waypoints.  With the waypoint tool enabled in the program, it is easy to point to a spot on the map, click, fill in the information box if necessary (default names are already given, but may be changed), click OK and go to the next spot.  Enabling the route tool lets you simply click each waypoint in sequence and you have a route.  This could be done on the GPS, but takes considerably longer.

I then downloaded the map into the GPS.  This is a simple one click on the download tool.  Everything else is set up by the program.  I could now view the Fishing Hot Spots map, which also included my waypoints and route that I had created with the MapSource program.  The GPSMap 162 has 2.5 MB of memory for map storage.  I eventually loaded 4 Fishing Hot Spot maps into it and used only 1.3 MB.  It obviously has plenty of map storage space for any of the Fishing Hot Spots maps you may need.  In this case none of the maps overlapped each other, but if they did, each individual map can be turned on or off.  Note:  While the CDROM's name is "Fishing Hot Spots",  it included much additional information such as: navigation buoys,  lights,  dam locations,  depth contours,  roads, marinas, parks and launching ramps around the waterways.

Installing the GPSMap 162 on the boat should be no problem for the typical boat owner who is always installing radios, depth finders, stereo systems, and the like.  In fact, this has fewer connections than many other items I have installed.  The unit was installed on a 37 ft. houseboat at the lower helm station.  A second station connection will be installed later on the flying bridge.  The antenna cable was routed through an existing cable tunnel to the upper deck and the antenna was mounted on the flying bridge structure.  Although there is a Bimini top on the bridge, it does not seem to interfere with the reception.

The Base map and the Fishing Hot Spots map can be turned on or off for the display.  Using only the base map we were quite often over dry land according to the GPS.  A warning message at the GPS startup states that the map is to be used as a reference only, and I found this to be quite true.  The river is about a mile wide here and narrows down as it goes upstream.  I would guess that we would be shown on land the majority of the time as we got further upstream.  Enabling the Fishing Hot Spots map made a world of difference.  It appeared to be quite accurate as we followed the shoreline.

Although I am not an avid fisherman, I checked with some of my friends who are and they seemed to be in general agreement that the fishing areas on the map were some of the best places to catch fish.  Of course, they each had their favorite spot which didn't coincide with anybody else's.  Using this map should increase your chances for a successful outing.

The locations of the navigation aids on the Fishing Hot Spots map were compared to the official river charts published by the U. S. Army Corps of Engineers instead of to their actual location.  They were found to be quite accurate and within 100 ft. or less of that shown on the charts.  When the channel buoys are pulled up for maintenance they are not always put back in the same spot, so comparing the Fishing Hot Spots map to the actual location would not be fair.  One buoy near here has moved up and down the channel over a half mile in the last 20 years.

All the marinas, parks and launching ramps are shown their correct locations, and the roads and streets near the lake are all properly named.  I have used other maps where this is not always true and is sometimes difficult to find a location.  The Fishing Hot Spots map showed a launch ramp that I had not noticed before, but it was there in the right location.  Being able to move the cursor to a marina or park and pressing ENTER to find out the facilities available is very convenient and informative.

By following the old stream beds and roads that are shown on the Fishing Hot Spots map, I was able to go back into bays and tributaries.  The lake is muddy and visibility in the water is nil, so knowing which side of the mouth of a bay has deep water is very important.  Using a depth finder along with the Fishing Hot Spots map indicated similar water depths, although silt has filled in some areas of the lake in the 40 some years it has been here.


I have enjoyed using the GPSMap 162 and the Fishing Hot Spots map, especially when navigating in unfamiliar water at night.  Even though the shorelines were over a mile apart, only about a 500 ft. width was deep enough to travel in, and that wiggled back and forth like a snake.  I came through with no warning sounds out of the depth finder.  Even in broad daylight in a river it is easy to get distracted and wander out of the channel.  Setting up a route beforehand and setting the OFF COURSE alarm will keep this from happening.

The only drawback I can find is that the GPSMap 162 has so many features that it is hard to remember them.  However they are logically placed in the Menu and pushing a few buttons will refresh the memory.

(Note that WAAS may not be satisfactory everywhere and there is nothing that can be done until the FAA gets more WAAS satellites available.)


On November 30, 2001 The Software was upgraded to version 3.03.  This corrected a few minor faults and modified some of the features to improve them and/or be consistent with other Garmin marine products.  It added support for the BlueChart Cartography which is now available on MapSource CD-ROM.  The "Go to Point" operation in navigation was changed to include a Find interface that improves finding a type of place, such as a waypoint, rest area, Interstate exit, etc.  If an Interstate exit is selected it will show the services available there.  Of course the points found depend upon the detail of the particular map loaded into memory.

The major change in the software was the manner in which the tide data information is stored.  Previously the tide data was included with the basic software and downloading version 3.03 eliminates that data.  It is now stored in the area of memory where the maps are stored.  You have two options for restoring the data: 1) You can download the original  data and load it into the memory, but any user loaded maps are erased.  Likewise, loading maps then erases the tide data.  2) The preferable way is to use MapSource compatible tide maps.  If you have a MapSource program that does not include tide data,  you download a MapSource version of the tide data maps, execute the program, and the tide maps become available in the MapSource program.  There are three maps that cover the U.S., including Alaska and Hawaii, Canada, and Mexico.  Selecting all three only takes up 162 Kb of memory out of the 2.5 Mb of map memory available, leaving plenty of space for maps.  Of course, maps from various MapSource products can be combined, as long as the total stays within the 2.5 Mb limitation.

The tide maps can now be used like any other user loaded map and can be turned off or on as desired.  When used by themselves, they will show all the tide stations available, of which there are hundreds.  You can get the tide data for any one of them by panning to it and pressing the Menu key.  The tide tab on the main menu lets you select the tide stations nearest you, or nearest another location that you can select from the map.  The date can be changed to show tide data for the future or past.

You can get the new software, the tide data and MapSource tide maps, plus full instructions AT NO CHARGE by going to and selecting Support, then Software Updates, then GPSMap 162 (or ) agreeing to the terms, and following the instructions on the page.

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