The Garmin eTrex 20 is one of several recent additions to the Garmin portable GPS lineup with a design aimed for multiple uses including the marine environment. This unit features a compact design, the ability to use a Garmin marine chart card, and is one of the smallest and lightest weight Garmin handheld GPS units available today.
The 20-series is a mid-level unit in the current eTrex line with features like removable memory card slot, high-sensitivity GPS receiver, and the ability to use BlueChart g2 marine chart cards as well as other land based Garmin cartography.
Unit Basics
The eTrex 20 measures only 4-inches high, 2.1-inches wide, and 1.2-inches thick. On my scale, it weighed in at a paltry 5-ounces with a pair of AA batteries installed. The eTrex package includes the unit itself, a USB cable, and an owner’s manual in English as well as 6 other languages.

Garmin eTrex 20
I tested the eTrex 20 with a BlueChart g2 marine chart covering the US and western Canada installed. With this chip in place this multi-purpose handheld becomes a full blown marine navigator capable of serving as your prime navigation tool on a small boat or a top notch backup on a larger vessel with hardwired navigation gear installed.
Controls
Several side-mounted pushbuttons and a joystick control this advanced eTrex. An up and down arrow button and menu key are located on the left side with the power and back button on the right, and the joystick on the front panel and serves as an enter button too.
The unit fits nicely in one hand and after some practice can be operated single-handed. If you use it in your right hand you can operate the joystick with your thumb and not block the screen.
Button labels for the pushbuttons are printed on the unit face. Black letters printed against a contrasting background color make the labels easy to read. One down side to the printed labels is the inability to read them under low light conditions as they are not backlit in any way.
Operation
The first time I turned on the unit it took about a minute to locate my position. On subsequent uses it locked on in seconds.

Lots of useful information is shown on the Trip Computer page. Data boxes can be changes as desired by the user.
The Garmin eTrex 20 is loaded with the latest version of Garmin’s intuitive and easy-to-use handheld software. This package gives the user access to function through a 24 menu listed main pages.
By default important pages, like Map, Where To?, Compass, Mark Waypoint, Trip Computer, and Setup are displayed on the top of the list on a single screen. The user can change the order of displayed pages if desired. Joystick control lets you highlight and select pages with ease.
Other pages of prime interest to mariners will be the Waypoint Manager, Route Planner, and Track Manager. With the BlueChart g2 installed you will find tide, current, and obstruction information located in individual submenus under the Where To? Page.
Screen Viewability
The Garmin eTrex 20 features a 2.2-inch (on the diagonal) 65,000-color TFT screen in portrait layout that carries a very respectable 176 x 220 pixel resolution. This combination makes the curved lines and small fonts on the map page sharp and easy to read.
As with any compact unit using a small screen, seeing details requires you have good vision while holding the unit close. Doing so will let you read fine details with relatively easily when conditions are benign. In rough seas, this unit, like all other small screen handheld GPS units may be difficult to read.

The Status page show present position at all times. It also gives the user a graphical display of satellite azimuth and signal strength.
We found the screen easy to see view under all tested lighting conditions. Fourteen different color palettes are available for both daylight and night viewing. No pushbutton backlighting is provided.
Odds and Ends
The battery compartment, USB port, and microSD card slot are all located on the case back. The microSD card slot is located inside the battery compartment and requires battery removal for access. A single twist lock opens and locks the battery compartment. The USB port is under a weather resistant cover at the top of the unit.
The accompanying USB cable allow data transfer of waypoint, route, track data, and screen shots between the eTrex 20 and a personal computer. The eTrex 20 will also transfer data wirelessly with another compatible unit.
The Garmin eTrex 20 can store up to 2000 waypoints and 200 routes. It carries a one-year warranty and is rated water resistant to IPX7 standards. That means it can be submerged to a depth of 1 meter for 30 minutes and not be damaged. This Garmin handheld GPS passed both our drop and submersion test with no issues to note. Be aware this unit does not float.
I liked the eTrex 20 for its fine color display screen, compact size, and user friendly software. To make this unit a real asset to mariners does require the addition of a BlueChart g2 marine chart covering your specific are of operation.