Garmin GNX 21 Marine Instrument with Inverted 4-Inch Display for Sailboats and Powerboats

GNX 21 Marine Instrument with Inverted Display - 4"

Marine Instrument with Inverted 4" LCD

• Large, easy-to-read white or color digits on a black background for high visibility in low-light or darkness; choose from 7 customizable backlight colors


• Glass-bonded display with anti-glare lens avoids fogging


• Fully customizable user profiles for sail or power boating to display most important marine and vessel data


• Low power consumption (25 mA) with 350 mW (no backlight)/400 mW (mid-level backlight)


• 5 display configurations plus gauge and graph mode to display depth, speed, wind and 50+ marine and boat parameters

The easy-to-read GNX 21 marine instrument has an inverted display with white or color digits on a black background that clearly shows depth, speed, wind and 50-plus marine and boat parameters. Its glass-bonded display with anti-glare lens coating provides excellent daytime and nighttime readability with high-contrast digits scalable up to 36 mm.

The GNX 21 is the first glass-bonded marine instrument with a combination of directly driven LCD segments and a dot-matrix field to display graphical information. Its low power consumption - (25 mA) with 350 mW (no backlight)/400 mW (mid-level backlight) - is perfect for use on sailboats, and provides a valuable instrument for cruising and fishing. Fully customizable user profiles display wind, depth and speed data. Plus, the GNX 21 includes an auto-scroll feature that rotates through data screens for hands-free operation. It can be installed with the included low profile flush mount or an optional flat mount for the ultimate glass helm solution and custom look for your boat.

Easy-To-Read Display

Unique high-contrast hybrid display features large, easy-to-read digits scalable up to 36 mm tall. Offers excellent clarity in direct sunlight, at dusk, or at night. The dot-matrix section can show additional details and/or graphical information.

Glass-bonded Display

Glass-bonded display helps prevent fogging, and the anti-glare lens finish increases visibility.

Customizable Color Digits

Choose from 7 different backlight colors, or even create a customized color, to achieve the screen that provides optimum readability for you.

Customizable User Profiles

Fully customizable user profiles allow you to choose from 5 available display configurations for sailboat or powerboat user-profiles: single, dual and triple function, plus gauge and graph mode to display wind, depth and speed data, or customize the pages to display the marine and boat data that is most important to you.

Auto Scroll

Set your display to automatically cycle between pages at a speed you set for convenient, hands-free operation.

Low Power Consumption

Perfect for sailors who want to sail for long intervals without having to run a motor or generator to charge batteries. The GNX 21 uses only 25 mA with 350 mW daytime usage, requiring no backlight and just 400 mW with a mid-level backlight setting at night.

NMEA 2000

Monitor more than 50 marine and boat parameters, including GPS speed, water depth and temperature, wind direction, and wind speed from the NMEA 2000 bus. You can also add a NMEA 0183 device using the optional 7-pin bare-wire power/data cable.

In The Box

• GNX 21


• Trim piece snap cover


• Protective cover


• Flush mount gasket and hardware


• NMEA 2000 T-connector


• NMEA 2000 drop cable


• Installation instructions


• Documentation

WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.

The Garmin GNX 21 Marine Instrument offers a highly visible, inverted 4-inch LCD display designed for optimal readability in various lighting conditions. Its large, high-contrast digits, scalable up to 36 mm, ensure clear visibility during daylight, dusk, or nighttime, making it ideal for both sailing and powerboating applications. The glass-bonded display with anti-glare coating prevents fogging and minimizes glare, delivering consistent clarity regardless of weather or lighting conditions. This instrument supports customizable backlighting with seven different colors, allowing boaters to tailor the display for maximum visibility in any environment. The GNX 21’s hybrid display combines directly driven LCD segments with a dot-matrix field, enabling the presentation of graphical information alongside vital marine data. Designed for efficient energy use, it consumes only 25 mA with 350 mW power in daylight mode and just 400 mW with a mid-level backlight at night, making it suitable for long cruises or fishing trips without taxing the vessel's power systems. Fully customizable user profiles allow the selection of up to five display configurations, including single, dual, and triple function modes, as well as gauge and graph views. These profiles enable sailors and boaters to prioritize information such as depth, speed, wind, and other key parameters relevant to their activity. The auto-scroll feature facilitates hands-free operation by cycling through different data screens at a user-defined pace, simplifying the viewing process during navigation. The GNX 21 interfaces seamlessly with NMEA 2000 networks, providing access to over 50 marine and boat parameters such as GPS speed, water depth, temperature, and wind data, with optional compatibility for NMEA 0183 devices. Its versatile mounting options include a low-profile flush mount or an optional flat mount, ensuring a sleek, customized look for your helm. Whether installed for long-term cruising or fishing, the Garmin GNX 21 delivers reliable, customizable marine instrumentation with superior readability and energy efficiency, making it an essential addition to any vessel's navigation suite. Included in the package are a protective cover, flush mount gasket and hardware, NMEA 2000 T-connector, drop cable, and comprehensive installation instructions, providing everything needed for a professional setup.

Features:

• Large, high-contrast digits scalable up to 36 mm for excellent daytime and nighttime visibility

• Glass-bonded, anti-glare display prevents fogging and enhances clarity

• Seven customizable backlight colors for optimal readability in any lighting condition

• Fully customizable user profiles with five display configurations for sail and powerboats

• Auto-scroll feature for hands-free data cycling at user-defined speeds

• Low power consumption of 25 mA with 350 mW daytime and 400 mW nighttime backlight settings

• Supports NMEA 2000 network for over 50 marine and vessel parameters, including GPS speed, wind, and water depth

• Versatile mounting options, including low-profile flush mount and optional flat mount

• Graphical and data display modes, including gauge and graph views for comprehensive vessel monitoring

• Includes protective cover, mounting hardware, NMEA 2000 T-connector, and installation instructions