The GPSMAP 421 is a compact chartplotter that features an ultra-bright 4� QVGA color display along with an improved high-speed digital design for increased map drawing and panning speeds. It’ s ready to go with a built-in, satellite-enhanced worldwide basemap and an easy-to-use interface designed to help you navigate the open waters with ease. The GPSMAP 421 also accepts BlueChart® g2 Vision cards for added features and functionality such as high-resolution satellite imagery, 3-D views and Auto Guidance technology.
View Satellite-enhanced Worldwide Basemap

The GPSMAP 421 basemap contains worldwide satellite images in place of traditional maps. The GPSMAP 421 also comes standard with a high-sensitivity GPS receiver for superior satellite tracking and quicker acquisition times. In addition, the GPSMAP 421 can receive U.S. graphical weather data via optional GXM 51 satellite receiver/ antenna. And with an SD card slot, it’ s easy to add additional maps without connecting to a computer.
Add Sonar

Where applicable, the sounder version, GPSMAP 421s, comes with a powerful dual-frequency transducer that clearly illustrates depth contours, fish targets and structures whether you’ re fishing in freshwater or off the coast. The GPSMAP 421 and GPSMAP 421s are also NMEA 2000-certified for easy connectivity with sensors, instruments and future marine offerings.
Add Extras with BlueChart g2 Vision

With the optional BlueChart g2 Vision SD card, you can add a whole new dimension of exceptional features to your chartplotter.

* MarinerEye view and FishEye view provide you a 3-dimensional perspective of map information, both above and below the waterline.
* High-resolution satellite images and aerial photographs help you orient yourself in unfamiliar areas.
* Auto Guidance technology searches through all relevant charts to create a route you can actually follow — one that avoids obstacles, shallow water, buoys and other obstructions.

Physical & Performance:
Unit dimensions, WxHxD: 5.7" x 5.0" x 2.7" ( 14.5 x 12.7 x 6.9 cm)
Display size, WxH: 2.4" x 3.2" , 4.0" diagonal ( 6.1 x 8.1 cm, 10.2 cm diagonal)
Display resolution, WxH: 240 x 320 pixels
Display type: QVGA display
Weight: 1.3 lb ( 590 g)
Battery: none
Battery life: none
Waterproof: yes ( IPX7)
High-sensitivity receiver: yes
Antenna: internal
NMEA input/ output: NMEA 0183 compatible and NMEA 2000 certified

Maps & Memory:
Basemap: yes
Preloaded maps: no
Ability to add maps: yes
Built-in memory: none ( cannot load maps to internal memory)
Accepts data cards: SDâ„¢ card slot
Waypoints/ favorites/ locations: 3, 000
Routes: 100
Track log: 10, 000 points; 50 saved tracks

Features:
Garmin radar compatible: no
Garmin sonar compatible: yes
CANet® compatible: no
Garmin Marine Networkâ„¢ compatible: no
Touchscreen: no
Supports AIS ( tracks target ships' position) : yes
Supports DSC ( displays position data from DSC capable VHF radio) : yes
Audible alarms: yes
Tide tables: yes
Hunt/ fish calendar: no
Sun and moon information: yes
3-D map view: yes ( with optional BlueChart g2 Vision card)
Auto Guidance: yes ( with optional BlueChart g2 Vision card)
Automatic routing ( turn by turn routing on roads) : no
XM WX Weather & Radio for U.S. & Canada compatible: yes
Voice prompts ( e.g. " Turn right in 500 ft." ) : no
Speaks street names ( e.g. " Turn right ON ELM STREET in 500 ft." ) : no
Remote control: no
Headphone jack/ audio line-out: no
Audio/ video input/ output: no
Portable: no
Automotive/ motorcycle-friendly: no