What is NMEA 2000? - The Offshore StoreThe Offshore Store

What is NMEA 2000?

Article by Matthew McGough

While most boaters are familiar with the marine electronics we commonly install on our vessels, such as fishfinders, multifunction displays (chartplotters), and VHF radios, what is often overlooked is the technology that networks those devices together. NMEA2000, sometimes referred to as NMEA2K or N2K, is the latest communications standard that allows marine electronics and sensors to talk to each other. NMEA2000 replaced NMEA 0183, which was only able to send information in one direction. NMEA 2000 added the capability to send information in both directions, to up to 50 devices, allowing for extensive control of many of a vessel’s systems.

Example NMEA 2000 Network. Image Courtesy of Simrad

NMEA2000 networks are similar to ethernet networks for home or business networking. The core of a NMEA2000 network is a backbone. A powered backbone runs throughout the vessel, connecting to each device. A drop cable connects each device to the backbone. Drop-cables should be as short as possible and should not exceed six meters or 18 feet. When designing a NMEA 2000 network, understanding the power requirements of the system, the maximum length of drop-cables, and the order of connection for your devices is important to achieving a reliable system.

NMEA 2000 networks, when used to their full capability, can be tremendously powerful. For example, we’ll consider a typical 40’ power cruiser and the systems onboard. Such a vessel would likely have at least one multifunction display, as well as a VHF radio, stereo system, sonar system, and potentially autopilot. A NMEA 2000 system can be utilized to maximize the capabilities of all these systems. The multifunction display contributes location data and course plotting that can be used by the autopilot and VHF radio. The stereo system can be controlled by the multifunction display. Sensors on the engine, generator, inverters, and battery chargers can be connected to the multifunction display to output speed, temperatures, voltage, fuel levels, alarms and much more, reducing the need for a cluttered helm full of gauges for every system. Auxiliary digital displays can be added that show any data that you choose. A heading sensor can be added to the network to increase the accuracy of the autopilot and chartplotter. In smaller boats, compatible trolling motors can be integrated into the NMEA 2000 system to allow for remote control and even autopilot functionality. The possibilities are truly endless, and all with a single communication standard that reduces the complexity of wiring and the need to route and endless amount of cables throughout the vessel.

While NMEA 2000 networks can seem intimidating, The Offshore Store offers a simple tool that you can use to receive a quote for all of the NMEA 2000 accessories needed for your desired setup, along with a diagram that can be used for DIY installation, or to give to an installer. The first step in designing your NMEA 2000 network is to choose the capabilities you desire and find and purchase the devices that offer those capabilities. Make sure to keep in mind compatibility between brands when making you choices. If you have any questions about NMEA 2000 accessories or NMEA 2000 compatible devices, reach out to The Offshore Store support at [email protected] or via the blue chat box located on the bottom-right of each page.

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