With the Garmin GPSMAP 640, you’ll get a full-featured marine chartplotter and an on-the-road navigator that comes ready to go with preloaded BlueChart g2 data and City Navigator NT road maps for North America. The GPSMAP 640 comes standard with a high-sensitivity GPS receiver and brilliant, high-resolution touchscreen display so you’ll always know the way whether you’re on land or at sea.

Specifications:
Display size, WxH: 4.5"W x 2.7"H (11.4 x 6.9 cm); 5.2" diag (13.2 cm) Display resolution, WxH: 800 x 480 pixels Display type: WVGA Battery: rechargeable lithium-ion Battery life: up to 9 hours	Waterproof: yes (IPX7) Antenna: internal NMEA input/output: NMEA 0183 RoHS version available: yes

Features: Touchscreen Supports AIS (tracks target ships' position) Supports DSC (displays position data from DSC capable VHF radio) Audible alarms Tide tables Sun and moon information 3-D map view (with optional BlueChart g2 Vision card) Auto Guidance (with optional BlueChart g2 Vision card) Automatic routing (turn by turn routing on roads) XM WX Weather & Radio for U.S. compatible Voice prompts (e.g. "Turn right in 500 ft.") (12v/speaker) Headphone jack/audio line-out Portable Automotive/motorcycle-friendly

Maps & Memory: Basemap: yes Preloaded maps: yes (coastal and detailed road maps) Ability to add maps: yes Built-in memory: internal solid state Accepts data cards: SD card slot Waypoints/favorites/locations: 1500 (marine mode); 1000 (automotive mode) Routes: 50 (marine mode); 10 (automotive mode) Track log: 10,000 points, 20 saved tracks (marine mode); 10,000 points, no saved tracks (automotive mode)