Why marine electronics often seem complicated

Many boating enthusiasts recognize the feeling that marine electronics seem complicated. Terms such as chartplotter, multifunction display (MFD), NMEA, backbone, and gateways are used interchangeably. And if you're new to the world of marine electronics, it feels like you first need to read a 200-page manual.

This is mainly because onboard systems function differently from consumer electronics at home. They must be robust against salt, vibrations, and variable voltages, and be able to process different data streams simultaneously. It often feels like everything needs to work at once, when all you really want to know is where you are, how deep it is, and what the wind is doing.

What does marine electronics include?

Marine electronics is the collective term for all electronic systems on board that collect, process, and display data. Together, these components form a single marine electronics system, where everything is connected via cables or networks.

• Navigation: chartplotters and displays that show your position, course, and route.
• Instruments: wind, depth, and speed through water, plus other readings.
• Communication: VHF radios and AIS for contact and overview.
• Network: NMEA 2000 backbone, drop cables, connectors, terminators, and gateways.

Chartplotter, MFD, and separate instruments, what's what?

A chartplotter is the device that displays your chart information. It shows your GPS position, your routes, and often additional information such as AIS targets. It is the heart of your navigation system.

An MFD (Multifunction Display) combines that chart information with other sources such as wind speed, depth, and AIS data on one clear screen. In practice, a modern chartplotter is almost always also an MFD, but not every MFD necessarily needs to display a chart.

Sometimes you also see separate instruments, for example a wind display in the cockpit so you can always read that information directly. The right combination depends on your sailing style and needs.

Sensors, where does all that data come from?

Without sensors, marine electronics won't work. They provide the data that is shared with your displays via NMEA. Without sensors, your screen is primarily a map without context.

• Wind sensor: wind direction and wind speed, essential for sailors.
• Depth sensor: real-time water depth, useful in shallow areas.
• Speed sensor: speed through the water.
• Heading sensor: course relative to north.
• GPS receiver: your exact position.

Onboard networks, why everything comes together

In a modern system, it's not necessary to connect every device directly. Through a network like NMEA 2000, sensors, displays, autopilot, and communication equipment can share data. This allows everything to work together instead of independently.

A good network gives you one overview of what's happening on board, without having to manage multiple separate cables. It also makes the system easier to expand if you want to add something later.

Tip: if you want to expand later, lay the foundation neatly now. This will save a lot of work and prevent malfunctions.

NMEA 0183 versus NMEA 2000

When discussing NMEA, you'll usually encounter two standards: NMEA 0183 and NMEA 2000. NMEA 0183 is the older standard where one device sends data to another via a serial connection. It works fine but has limitations in speed and how many devices you can connect neatly at once.

NMEA 2000 is the more modern standard. It's a true network where multiple devices can share data simultaneously over a central backbone. Many boaters specifically search for "what is NMEA 2000" or "NMEA 2000 explanation" because this is now the standard for new installations.

Backbone, spur, and terminators, a simple explanation

In an NMEA 2000 network, you'll almost always encounter three terms. If you understand these, you'll understand most of "setting up an NMEA network."

• Backbone: the main network cable carrying all data.
• Spur: a branch from the backbone to a sensor or display, often via a T-connector.
• Terminators: resistors at both ends of the backbone that ensure the network remains stable.

Problems in an NMEA 2000 network can often be traced back to the backbone or terminators. If your backbone is not correctly terminated or you use spur cables that are too long, it can lead to outages or flickering data. A tidy backbone with good terminators is therefore the basis for a reliable system.

Can you combine old and new?

Many boaters still have older instruments that work on NMEA 0183. You don't always have to replace them immediately when switching to NMEA 2000. With a gateway, you can connect older equipment to your modern network so you can continue to use it.

This is often seen on boats that have been expanded over the years. It can save costs and allows for phased upgrades.

Install it yourself or have it done?

Many boaters choose to install their backbone themselves and run drop cables to sensors. This is perfectly fine if you are handy and understand the structure. Think about power supply, correct cable lengths, and properly placing terminators.

Problems often arise from missing terminators, incorrect power supply, or overly long spur cables. For more complex systems with multiple displays, autopilots, or radar, it is wise to have a specialist take a look to ensure everything works reliably.

How to build for the future?

If you're investing in marine electronics now, think ahead. Choose components that you can easily expand with additional sensors or displays. Use networks like NMEA 2000 to maintain flexibility in your choices later on.

A solid backbone, good terminators, and quality components ensure that your system is ready for the future and remains easily expandable. This way, you avoid having to start over in a few years.