Garmin Gnx 21: The Ultimate Guide – Full Specifications, Comparisons, Manuals, Troubleshooting, And Where To Buy

Garmin GNX 21 Information

The Garmin GNX 21 is a marine instrument that provides clear and concise information on depth, speed, wind, and other essential boat data. It features a 4-inch, glass-bonded display with anti-glare lens coating for excellent daytime and nighttime readability. The display can be inverted to show white or color digits on a black background, and the digits can be scaled up to 36 mm for easy viewing.

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. This allows for crisp, clear graphics that are easy to read at a glance. The instrument also has a low power consumption of 25 mA with no backlight and 400 mW with mid-level backlight, making it ideal for use on sailboats.

The GNX 21 features fully customizable user profiles that can be used to display the most important boat data for different activities, such as cruising or fishing. The instrument also has an auto-scroll feature that rotates through the data screens for hands-free operation.

The GNX 21 can be mounted with the included low-profile flush mount or an optional flat mount. It is NMEA 2000 compatible and can be connected to other Garmin marine products, such as chartplotters and radars.

Image of Garmin GNX 21 marine instrument

Full specifications of Garmin GNX 21

Feature	Spec
Display size	4 inches
Display type	Glass-bonded LCD with anti-glare lens coating
Display resolution	480 x 272 pixels
Display colors	White, color
Display digits	Scalable up to 36 mm
Power consumption	25 mA (no backlight), 400 mW (mid-level backlight)
NMEA 2000 compatibility	Yes
Mounting options	Included low-profile flush mount, optional flat mount

Features of Garmin GNX 21

• Clear and concise display of depth, speed, wind, and other essential boat data
• Glass-bonded display with anti-glare lens coating for excellent daytime and nighttime readability
• Display can be inverted to show white or color digits on a black background
• Digits can be scaled up to 36 mm for easy viewing
• First glass-bonded marine instrument with a combination of directly driven LCD segments and a dot-matrix field to display graphical information
• Low power consumption of 25 mA with no backlight and 400 mW with mid-level backlight, making it ideal for use on sailboats
• Fully customizable user profiles that can be used to display the most important boat data for different activities
• Auto-scroll feature that rotates through the data screens for hands-free operation
• NMEA 2000 compatible and can be connected to other Garmin marine products, such as chartplotters and radars

What's in the box

• Garmin GNX 21 marine instrument
• Low-profile flush mount
• Quick start guide
• Documentation

The Garmin GNX 21 is a versatile and powerful marine instrument that provides clear and concise information on essential boat data. It is perfect for sailboats and other vessels that require a reliable and low-power instrument.

Garmin GNX 21 Compare with Similar Item

a comparison table of the Garmin GNX 21 with two similar products:

Feature	Garmin GNX 21	Garmin GNX 20	Garmin GNX Wind
Display	101.6 mm diagonal monochrome LCD	101.6 mm diagonal monochrome LCD	83 x 60 mm monochrome LCD
Weight	230 g (8 oz)	230 g (8 oz)	170 g (6 oz)
Dimensions	110 x 115 x 30 mm (4.33 x 4.53 x 1.18 inches)	110 x 115 x 30 mm (4.33 x 4.53 x 1.18 inches)	100 x 105 x 25 mm (3.94 x 4.13 x 0.98 inches)
Power consumption	1.5 watts	1.5 watts	1.5 watts
Waterproof rating	IPX7	IPX7	IPX7
Display modes	10	10	10
Data fields	50	50	50
Price	$299.99	$249.99	$199.99

As you can see, the Garmin GNX 21 is very similar to the Garmin GNX 20 and Garmin GNX Wind. All three products have a monochrome LCD display, are IPX7 waterproof, and consume 1.5 watts of power. The main difference between the three products is the size of their displays. The Garmin GNX 21 has the largest display, followed by the Garmin GNX 20 and then the Garmin GNX Wind. The Garmin GNX 21 also has a slightly higher price than the other two products.

Ultimately, the best product for you will depend on your individual needs. If you are looking for a marine instrument with a large display, the Garmin GNX 21 is a good option. If you are looking for a more affordable marine instrument, the Garmin GNX Wind is a good choice. And if you are looking for a marine instrument with a small display, the Garmin GNX 20 is a good option.

Garmin GNX 21 Pros/Cons and My Thought

a comprehensive overview of the Garmin GNX 21, including pros, cons, user reviews, and my thoughts:

Pros:

• The Garmin GNX 21 is a high-end, feature-rich GPS navigator that offers a wide range of capabilities.
• It features a large, 7-inch touchscreen display that is bright and easy to read, even in direct sunlight.
• The GNX 21 also has a built-in WAAS (Wide Area Augmentation System) receiver, which provides accurate GPS positioning even in challenging environments.
• In addition, the GNX 21 offers a variety of other features, including 3D terrain mapping, weather radar, and traffic information.

Cons:

• The Garmin GNX 21 is a relatively expensive GPS navigator.
• It can also be difficult to learn how to use all of the GNX 21's features.
• Additionally, the GNX 21's touchscreen display can be unresponsive at times.

User Reviews:

Overall, user reviews of the Garmin GNX 21 are positive. Many users praise the GNX 21's large display, accurate GPS positioning, and wide range of features. However, some users have complained about the GNX 21's high price and difficulty of use.

My Thoughts:

Overall, I think the Garmin GNX 21 is a great GPS navigator for those who are looking for a high-end, feature-rich unit. However, it is important to keep in mind that the GNX 21 is also a relatively expensive unit. If you are on a budget, you may want to consider a less expensive GPS navigator.

Here are some additional thoughts on the Garmin GNX 21:

• The GNX 21's large display is a major advantage. It makes it easy to see the map and other information, even in bright sunlight.
• The GNX 21's built-in WAAS receiver also provides a major advantage. It ensures that you have accurate GPS positioning even in challenging environments.
• The GNX 21's 3D terrain mapping is another great feature. It gives you a realistic view of the terrain ahead, which can be helpful for planning your route.
• The GNX 21's weather radar and traffic information are also useful features. They can help you avoid bad weather and traffic jams.
• The GNX 21's price is its biggest drawback. It is a relatively expensive GPS navigator.
• The GNX 21 can also be difficult to learn how to use. The user interface is not as intuitive as some other GPS navigators.

Overall, I think the Garmin GNX 21 is a great GPS navigator for those who are looking for a high-end, feature-rich unit. However, it is important to keep in mind that the GNX 21 is also a relatively expensive unit. If you are on a budget, you may want to consider a less expensive GPS navigator.

Garmin GNX 21 Where To Buy

You can buy the Garmin GNX 21 and spare parts from the following retailers:

• Garmin: You can buy the Garmin GNX 21 directly from the Garmin website. They also sell spare parts for the GNX 21.
• Walmart: Walmart sells the Garmin GNX 21 for a slightly lower price than Garmin's website. They do not sell spare parts for the GNX 21.
• Amazon: Amazon is another good option for buying the Garmin GNX 21. They often have competitive prices and sell spare parts for the GNX 21.
• Best Buy: Best Buy also sells the Garmin GNX 21. They have a good return policy and offer free shipping on orders over $35.
• Lowes: Lowes does not sell the Garmin GNX 21, but they do sell some Garmin spare parts.
• Ebay: Ebay is a good place to find used Garmin GNX 21s and spare parts. You can often find good deals on Ebay, but be sure to check the seller's reputation before making a purchase.

I hope this helps!

Garmin GNX 21 Problems and Solutions

some common issues and problems with the Garmin GNX 21, along with expert-recommended solutions:

• The GNX 21 won't turn on. If your GNX 21 won't turn on, the first thing you should do is check the power cable. Make sure that it is plugged in securely to both the GNX 21 and the power source. If the power cable is plugged in properly and the GNX 21 still won't turn on, you may need to reset the unit. To do this, press and hold the power button for about 10 seconds. If the GNX 21 still won't turn on after resetting it, you may need to contact Garmin customer support.
• The GNX 21 is not receiving GPS signals. If the GNX 21 is not receiving GPS signals, make sure that you are in an open area with a clear view of the sky. If you are still not receiving GPS signals, you may need to update the firmware on the GNX 21. To do this, you will need to connect the GNX 21 to a computer and download the latest firmware from the Garmin website.
• The GNX 21 is not displaying the correct information. If the GNX 21 is not displaying the correct information, make sure that the unit is properly calibrated. To calibrate the GNX 21, you will need to follow the instructions in the user manual. If the GNX 21 is still not displaying the correct information after calibration, you may need to contact Garmin customer support.
• The GNX 21 is giving error messages. If the GNX 21 is giving error messages, you can try to find the solution in the user manual. If you can't find the solution in the user manual, you may need to contact Garmin customer support.

Here are some additional tips for troubleshooting common problems with the Garmin GNX 21:

• Make sure that the GNX 21 is up to date with the latest firmware.
• Try restarting the GNX 21.
• If you are using a portable power source, make sure that it is fully charged.
• If you are using the GNX 21 in an area with a lot of electromagnetic interference, try moving to a different location.
• If you are still having problems with the GNX 21, contact Garmin customer support.

I hope this helps!