The GNX 20 and GNX 21 are fully custmizable instruments and can show data from more than 50 different data sets from the NMEA 2000 bus [we guess] The data items can be combined on the display in up to 3 different data sources at any one time. You can also select to get the data on a graph or as a gauge.
The data in the GNX 20 and GNX 21 can be “rotated” on user selected time schedules – so one instrument can show a multitude of different data. I wonder [hope] if it can tie in with Garmins helm profile selection system – where one button press on a chartplotter – can change setup on all chartplotters. That means you can have a cruise profile, anchor profile, race profile and so on – and your instruments adapts to what is sensible to show in that profile. That would be really neat.
They both have 4″ glass-bonded monochrome displays – but the GNX 20 is white
background with black text where the GNX 21 is black background with white text. So both has high visibility without backlight during the day. For night time you can select a subtle backlight from a range of 7 different colours. Both displays can be flush- or flat-mounted.
The power consumption is very low – 350 mW without backlight and 400 mW with middle strength backlight. 350 mW is equal 0.028 Ampere on a 12 volt system. So VERY low power consumption. My Maretron DSM 250 takes 0.600 ampere at full backlight, but that is kind of outdated…
As Garmins links to the detail pages are not working yet – I’ll update with direct link later. But until then – Garmin says the instruments will be available in 2. Quarter of 2014 and will have a suggested retail price of $449.99