Steering clear of trouble just got easier

The GMR 20 adds important radar information to a system that already includes GPS, sonar, and XM WX Satellite Weather data components—making our Marine Network one of the most comprehensive marine navigation systems on the market.

Digital Performance

The GMR 40 (2kW radome) features a narrow 3.6-degree horizontal and 25-degree vertical beamwidth, which delivers accurate target acquisition and better penetration through rain and fog. It has a range of 36 nautical miles (nm). For fast and efficient presentation of radar signatures, raw data is processed within the radome and presented on Garmin’s GPSMAP 3000 series chartplotter/multifunction displays (MFDs).

Easy to Use

The GMR 40 features automatic and manual sensitivity and tuning controls, including gain, sea clutter, and rain clutter—which allows boaters to spend less time tuning the unit and more time navigating. The unit also boasts selectable interference rejection, which mitigates the effect of nearby radar transmissions.

To aid in collision avoidance, the unit also offers Mini Automatic Radar Plotting Aid (MARPA) capability, which allows boaters to track the bearing, course, speed and predicted closest approach (by both time and distance) of up to 10 targets. MARPA functionality requires GPSMAP 3006/3010 MFDs and an optional heading sensor.

Advanced Features

Once the GMR 40 is interfaced with a GPSMAP 3000 series MFD, it is possible to overlay radar images on the charting to help reconcile radar signatures with known objects. Users can view "radar only" or split the display for multiple views of radar and charting.

Plug-and-play Connectivity

The GMR 40 communicates with the Garmin Marine Network through a waterproof 100-megabit plug-and-play proprietary network—which affords users the ability to expand their boat’s system as needed. Boaters can connect a GPS antenna and one remote network sensor (like the GMR 40) directly to the MFD—or with the addition of the GMS™ 10 Network Port Expander, users can connect multiple MFDs and network sensors to the same network.

The GMR 40: Giving boaters more confidence and enjoyment on the water.



Garmin part number: 010-00324-00

Suggested Retail Price:
$2346.65 U.S.D. (for domestic US market only)

Expected Availability:

Now Shipping