The Garmin GMR™ 18 xHD3 (010-02841-00) is a high-definition 18-inch, 4 kW magnetron dome radar designed to deliver long-range target detection up to 48 nautical miles and short-range detail down to 20 meters. Featuring dual rotation speeds of 24 and 48 RPM, it provides rapid screen refresh rates on compatible Garmin chartplotters to enhance situational awareness in high-traffic waters. Advanced processing features include scan-averaging technology to reduce sea clutter, target-size processing to improve target definition, and dual-range monitoring to track near and far targets simultaneously on a split screen. The system supports Auto Bird Gain for locating flocking sea life, MARPA target tracking for up to 30 targets, chartplotter radar overlay, and Dynamic Auto Gain and Sea Filtering. Housed in an IPX7-rated radome powered by a low-noise motor drive, it operates on 11 to 32 VDC power, connects via the Garmin Marine Network, and comes supplied with a 15-meter power and network interconnect cable.

In the Box

GMR 18 xHD3 dome radar (depending on model selected)
Power cable (15 m/49.21 ft)
Network cable (15 m/49.21 ft)
Mounting hardware kit and template
Installation instructions

Technical Specification

General
Antenna Length	18: 17″ (43 cm) 24: 23″ (58 cm)
Rotation speed (RPM)	Up to 60 rpm, depending on settings
Dimension	18: 20″ x 9.8″ (508 mm x 248 mm) 24: 25.4″ x 9.8″ (64.5 cm x 24.9 cm)
Weight	18: 7.0 kg 24: 8.7 kg
Water rating	IPX7
Beam width	18: 5.2° horizontal, 25° vertical 24: 3.7° horizontal, 25° vertical
Maximum range	48 nm
Minimum range	20 meters
Radar type	Radome

Electrical Features
Power Input	11-32 V DC
Power Consumption (standby)	15 W
Typical power consumption, transmitting (normal mode)	40 W
Transmit power	4 KW

Radar Features
Dual range	✓
Overlay	✓
Dual radar support	✓
Auto Bird Gain	✓
Auto Gain	Dynamic
MARPA target tracking	yes (requires heading sensor, sold separately)
Echo Trails	True
Target size	✓
Scan averaging	✓