NMEA 2000 is a combined electrical and data specification for a marine data network for communication between marine electronic devices such as depth finders, nautical chart plotters, GPS receivers, navigation instruments, engines, tank level sensors, weather stations, temperature and distributed electrical power control systems. It has been defined by, and is controlled by, the US based National Marine Electronics Association (NMEA).

The NMEA 2000® standard contains the requirements of a serial data communications network to inter-connect marine electronic equipment on vessels. The standard describes a low-cost moderate capacity bi-directional, multi-transmitter/multi-receiver instrument network to interconnect marine electronic devices.

It is multi-master and self configuring, and there is no central network controller. Equipment designed to this standard will have the ability to share data, including commands and status with other compatible equipment over a single channel. It is based on CAN (Controller Area Network). All NMEA 2000® products must be certified by NMEA. Although this standard is 50 times faster than NMEA 0183, it is not intended to support high-bandwidth applications such as video.