When building or upgrading your boat's electronics network, you'll quickly encounter two terms: NMEA 2000 and SeaTalkNG. If you're installing Raymarine equipment alongside other brands, understanding the relationship between these protocols is essential. The good news? They're more compatible than you might think.
What is NMEA 2000?
NMEA 2000 is the marine industry's standard communication protocol, allowing different electronic devices to share data on a single network. Think of it as the universal language that lets your GPS, autopilot, depth sounder, wind instruments, and chartplotter all talk to each other—regardless of manufacturer.
The protocol uses a Controller Area Network (CAN bus) backbone with standardised connectors (typically Micro-C or DeviceNet) and operates at 250 kilobits per second. Any NMEA 2000 certified device should work with any other certified device, making it the foundation of modern integrated marine electronics.
What is SeaTalkNG?
SeaTalkNG is Raymarine's implementation of the NMEA 2000 standard. It uses the same underlying protocol and data structure as NMEA 2000, but Raymarine designed their own connector system and cabling to make installation simpler and more robust in the marine environment.
SeaTalkNG connectors feature a bayonet-style locking mechanism that's easier to connect and disconnect than standard NMEA 2000 Micro-C connectors, and they're designed to be more waterproof and corrosion-resistant.
The Key Difference: It's Just the Connectors
Here's the crucial point: SeaTalkNG and NMEA 2000 are electrically and functionally identical. The only difference is the physical connector. The data flowing through the cables is exactly the same, which means the systems are fully compatible—you just need the right adapters.
Can You Mix SeaTalkNG and NMEA 2000 Devices?
Absolutely. You can build a hybrid network using both SeaTalkNG and NMEA 2000 devices, and Raymarine provides multiple adapter options to make this seamless.
SeaTalkNG to DeviceNet Adapter Cables
Raymarine offers two types of adapters for connecting SeaTalkNG and DeviceNet (the most common NMEA 2000 connector standard):
Spur adapters (A06045): These allow you to connect individual NMEA 2000 devices to a SeaTalkNG backbone via a T-piece or spur connection. Perfect for adding a single third-party sensor, GPS antenna, or instrument to your SeaTalkNG network.
Backbone adapters (A06031): These connect SeaTalkNG backbone cable directly to DeviceNet backbone cable, allowing you to run both cable types on the same system. This is ideal when you want to extend your network using whichever cable type is most convenient for a particular installation area, or when integrating an existing DeviceNet network with new SeaTalkNG components.
This flexibility means you can truly mix and match—running SeaTalkNG cable in the cockpit where you have Raymarine displays and instruments, then transitioning to DeviceNet backbone cable in the engine room where you're connecting third-party engine monitoring or tank sensors.
Building Your Hybrid Network
When creating a mixed network, you have complete freedom:
- Use adapter cables: Connect standard NMEA 2000/DeviceNet devices to a SeaTalkNG backbone, or vice versa
- Choose your backbone: Use SeaTalkNG cable in some areas and DeviceNet in others, joined with backbone adapters
- Mix and match devices: Connect Raymarine instruments to a DeviceNet network, or add third-party sensors to your SeaTalkNG system
- Expand strategically: Start with one cable type and add the other as your system grows
Practical Considerations
When building a mixed network, keep these points in mind:
Connector reliability: SeaTalkNG connectors are generally considered more robust and easier to work with, so some installers prefer to use SeaTalkNG backbone cable in exposed areas even when connecting non-Raymarine devices.
Power distribution: Both systems can provide power to devices over the network (LEN/load equivalency), but ensure your power budget is properly calculated regardless of which cabling you choose.
Termination: Both ends of your backbone must be properly terminated with 120-ohm terminators—SeaTalkNG and NMEA 2000 terminators are electrically identical. If you're running both cable types, you only need terminators at the two physical ends of the combined backbone.
Cable length limits: The same NMEA 2000 network length rules apply (200m maximum total backbone length, device drop cables typically 6m maximum), regardless of whether you're using SeaTalkNG, DeviceNet, or a combination.
Adapter placement: Plan your adapter locations thoughtfully—it's easier to transition between cable types at junction points rather than mid-run.
When to Choose Each System
If you're running primarily Raymarine equipment, a SeaTalkNG backbone makes sense for the superior connectors and simplified installation. If you're integrating multiple brands or already have DeviceNet infrastructure, you can stick with standard DeviceNet and use spur adapters for Raymarine devices, or create a hybrid backbone using both cable types where each makes the most sense.
The Bottom Line
Don't let connector differences limit your equipment choices. SeaTalkNG and NMEA 2000 are the same protocol with different plugs. With spur and backbone adapter cables, you can build a robust, multi-brand network that shares data seamlessly across all your marine electronics—using whichever cable type is most practical for each section of your installation.
Whether you're adding a Raymarine autopilot to an existing DeviceNet network, connecting third-party sensors to your SeaTalkNG system, or running both cable types throughout your vessel, compatibility is straightforward and reliable.
Need help planning your marine electronics network? Our team can advise on component selection, network design, and professional installation to ensure your systems communicate flawlessly.
