Don’t Buy Any Electronics….


until you know all about NMEA 2000. (NMEA is pronounced “neema”) I recently attended an NMEA 2000 seminar and believe me, you need to know lots before you buy any electronic devices.

In the Past

As most of us know, adding electronics to older boats meant miles of spaghetti wiring around your helm and to each of your electronics—and they only worked together if they were the same brand.


Spaghetti Wiring Under Helm

 Each unit required a pair of wires running back to the power and ground source plus several other cables that carried data from transducers and senders. Old electronics could not share data from manufacturer to manufacturer and in many cases, not share from model to model. Plugs were not interchangeable and wire color coding varied and language was different. Displays were painfully slow to redraw. All these independent units pulled a lot of power from your batteries. Sound familiar?

Now NMEA 2000

Now, at last, there is standardization. All the major electronics manufacturers and motor manufacturers have developed this new standardized system to be used universally by all of them. Now there is a single data language, wiring color code, cabling, connectors and plugs. This new CAN (Control Area Network) is instantaneous—called “real time control”, so it’s much, much quicker than before and requires less power.

The new system is NMEA 2000. It’s a new standardized network system that allows you to add new components to your boat over time or all at once all on one cable. All units can communicate with each other, even if they are different brands from different manufacturers.

Before purchasing new electronics for your boat this spring or summer, check to verify that each is “NMEA 2000” certified compatible—National Marine Electronics Association.

How it Works

Think of how the electrical suppliers set up a trade show. They start by running a cable along the back of a long row of 10’ x 10’ booths. The cable has electrical outlets installed at set intervals. Each booth that needs power, simply plugs in their individual power bars and cords. This setup is cleaner, neater, saves hundreds of feet of extension cords running from each booth along the wall all the way back to the power source/panel box. It’s not only neater, more efficient and uses far less wire, it is also safer and saves power.


Backbone with “T” Connectors & Drop Cables to Electronics

The backbone of the new NMEA2000 network is a cable that comes with a series of “T” connectors that each unit connects to for power, ground and data transmitting. Say goodbye to the miles of spaghetti wire around your helm required for the old system that dates back to 1983.




“T” Connector


Instead of outlets for plugging into our Trade Show example, the NMEA2000 cable utilizes standardized “T” connectors for a more permanent connection than an electrical plug and outlet. The standardized cable with standardized colored wire is available with a series of connection points i.e., “T” Connectors.





Drop Cable

Each piece of electronics is simply plugged into the cable with standardized waterproof connectors and the required length of “drop cable” from the backbone cable. If required, extra “T” connectors can be added anywhere into the cable. The system does not require a central network controller, so it is multi-mastered. Equipment is designed to share both data and commands with other compatible equipment over this single cable or channel. You just add units from various manufacturers or all the same—your choice. It’s like a building block process that can grow as and when you want.

Data from the newer electronically controlled outboard and sterndrive motors can be shown on the new multi-function display monitors. Additional sensors can be added for high water, CO, etc. Just plug these sensors into the cable.

Some new boat and yacht builders are including and utilizing the NMEA2000 network cable for connecting gauges, instrumentation, plus standard and optional electronics at the factory, anytime at the dealership and later at the owner’s leisure.

Newer models of marine electronics that are NMEA 2000 compatible from Furuno, Garmin, Lowrance, Raymarine, Simrad and many, many others can be connected to the same network and utilize data from each other.


System Diagram


This is the latest standard for serial data networking for marine electronic devices both for navigation and radio communications that meets global safety requirements.


Technically speaking, the NMEA 2000 is a bi-directional multi-transmitter/multi-receiver instrument network to interconnect electronic equipment. The connectors and cables used are compatible forming the controller area network, which permits a versatile system to be established with a minimum of effort and at a reasonable cost.

The Benefits

The benefits to you, the boater, are that marine electronic devices from different manufacturers can communicate with each other and operate efficiently and safely through a single standardized cable. Equipment built to NMEA 2000 standards can share data and commands on your boat’s network. You can make choices of the products that you want on your network from various sources and add them when you want to. They are also easy to disconnect and remove for repair or for a technician to connect up a laptop to troubleshoot a problem.

Before you Buy

If you are in the market for electronics this year, check to make sure the unit is NMEA 2000 compatible. There is no sense spending money on old technology.

If you do upgrade to the new NMEA 2000 Cable, you can get an AT-10 made by Simrad that is an NMEA 2000 to 0183 converter allowing you to interconnect some older products with the new NMEA 2000. This allows you to continue using your old products as you slowly upgrade to the newer products.



For some recent electronics that were manufactured prior to the NMEA 2000 standardization, check your model with its manufacturer regarding convertibility.

 Even if you don’t upgrade your old system with a new NMEA 2000 Cable, a new NMEA 2000 device will work in parallel to (but not with) your old system. You can use it, but it won’t talk to your old system.

When you get a new boat that has a NMEA 2000 cable, you can just take your NMEA 2000 compatible electronics with you and plug them in if you want to.

For More Information

Everything else that you may want to know about this new network for marine electronics is available at NMEA 2000 and the various marine electronics manufacturers’ websites—just Google the brand.

Shop Knowledgeably to keep up with technology

Happy Boating,

by Doug Dawson

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