Garmin GMR™ 18 xHD3 Radome

Garmin GMR™ 18 xHD3 Radome

Garmin GMR™ 18 xHD3 Radome  are a high-definition radome that brings professional-grade features to a compact, user-friendly design.

Garmin GMR™ 18 xHD3 Radome: Professional Performance in a Compact Dome
At Morgan Marine, we understand that confidence at sea is paramount. Whether you are navigating through thick coastal fog or heading offshore for a day of fishing, the Garmin GMR™ 18 xHD3 provides the clarity and reliability you need. This 4kW magnetron radar combines the space-saving benefits of an 18-inch dome with advanced scanning features usually reserved for much larger open-array units.

The xHD3 series represents a significant leap forward in magnetron technology. With the introduction of Scan Averaging, a first for Garmin magnetron radars, the system intelligently filters out sea clutter and interference. This results in a much cleaner display, allowing you to identify consistent targets like buoys and other vessels with ease.

For the keen anglers among our customers, the Auto Bird Gain feature is a game-changer, helping you locate flocks of birds at the water's surface—a sure-fire sign of baitfish and the larger predators below. Combined with a 48-nautical mile range and a high-speed 60 RPM rotation for rapid screen updates, the 18 xHD3 ensures you never miss a thing.

Garmin GMR™ 18 xHD3 Radome Key Features

• Advanced Scan Averaging: Filters out sea clutter and interference to enhance the detection and display of consistent targets for a clearer picture.
• Precision Target Processing: Features angular target-size adjustment and pulse expansion to optimise on-screen object shapes, making them easier to interpret at all ranges.
• High-Speed Scanning: Rotation speeds of up to 60 RPM improve the redraw rate, giving you near-instant updates on fast-moving targets and changing weather conditions.
• True Echo Trails: Displays a historical "trail" of vessels on your screen, helping you quickly identify moving targets and assess potential collision threats.
• Dual Range with Overlay: View short and long-range views simultaneously on a split-screen. You can also overlay radar data directly onto your chartplotter’s map for intuitive navigation.
• Target Tracking (MARPA): Track up to 30 targets to help you stay aware of other vessels in your vicinity (requires a heading sensor, sold separately).
• Guard Zones: Set custom safety zones and receive an instant alarm if any object enters your designated perimeter.
• Quiet and Efficient: The refined dome drive motor operates with minimal noise and low power consumption, making it ideal for smaller vessels.
• Robust & Reliable: Fully IPX7 waterproof rated and built to withstand the harsh conditions of the British coastline.

In The Box:

• • GMR 18 xHD3 dome radar
  • Power cable (15 m)
  • Network cable (15 m)
  • Mounting hardware kit and template
  • Installation instructions

Morgan Marine Expert Tip: To get the most out of features like Radar Overlay and MARPA, we recommend pairing this unit with a Garmin heading sensor. Speak to our team today if you need advice on compatibility or professional installation services.

Garmin GMR™ 18 xHD3 Radome FAQs

What makes the xHD3 different from the older xHD series?

The xHD3 is a significant step up. The standout addition is Scan Averaging, which is a first for Garmin magnetron radars. It cleverly filters out "noise" from the sea and weather, leaving you with a much cleaner image of actual targets. It also features a faster rotation speed (up to 60 RPM), meaning the picture on your screen updates much more quickly—vital when you’re navigating busy shipping lanes or avoiding fast-moving craft.

Does this radar help with finding fish?

Absolutely. It features a dedicated Auto Bird Gain mode. This allows you to locate flocks of birds at the water's surface from a distance, which, as any experienced angler knows, is the best way to find schools of baitfish and the larger game fish following them.

Is it difficult to distinguish between two boats close together?

No, thanks to the Angular Target-Size Adjustment. This technology uses pulse expansion to sharpen the shapes of objects on your screen. Instead of seeing one large "blob," the xHD3 helps you see two distinct targets, giving you much better situational awareness in tight spots or crowded harbours.

Can I see the radar and my chart at the same time?

Yes. The xHD3 supports Dual Range with Overlay. This means you can have a split-screen showing a close-in view for pilotage and a long-range view for weather or traffic. You can also overlay the radar return directly onto your Garmin chartplotter’s map, so you can see exactly where a radar target sits in relation to buoys or landmasses.

What is MARPA and do I need anything extra for it?

MARPA (Mini-Automatic Radar Plotting Aid) allows you to select and track up to 30 targets, showing you their speed, heading, and closest point of approach (CPA) to help avoid collisions. To use this feature (and the Radar Overlay feature), you will need a heading sensor (sold separately), which provides the radar with the precise direction your boat is facing.

How much power does it draw?

It’s remarkably efficient for a 4kW unit. It typically draws about 40W while transmitting and only 15W in standby mode. This makes it a great choice for sailing yachts or smaller motorboats where battery management is key.

Will it fit on my existing mount?

The GMR 18 xHD3 uses a standard Garmin 18-inch footprint (508mm diameter). If you are replacing an older Garmin 18-inch radome, it should bolt straight onto your existing mount or mast bracket. If you're unsure, just give us a ring at the shop and we can check your specific setup.

Is it noisy?

Not at all. Garmin has used a very quiet dome drive motor in this generation. Even at the high-speed 60 RPM setting, you’ll barely hear it from the cockpit, which is a real plus during long night passages.

What comes in the box?

When you buy from Morgan Marine, you get the complete kit: the GMR 18 xHD3 radome, a 15-metre power cable, a 15-metre network cable, the mounting hardware kit with a template, and full instructions.

Is my current Garmin Chartplotter compatible?

The xHD3 is designed to work with the latest Garmin GPSMAP® series (such as the 723, 923, 1223, and 8400 series). If you have an older unit or an ECHOMAP™ series plotter, please contact us first so we can verify compatibility for you.

Still have a question?

The Morgan Marine team is always on hand to help you get your electronics right the first time. Visit us at the marina or drop us a message through the store!