Overview of OneNet
OneNet is the National Marine Electronics Association’s newest networking standard for marine electronics, positioned as the successor to NMEA 2000®. Unlike its predecessors (NMEA 0183 and NMEA 2000), OneNet is built on modern Internet protocols, using IPv6 over standard Ethernet (IEEE 802.3). This means that OneNet-enabled devices connect via an Ethernet network (rather than a CAN-bus backbone) and communicate using Internet Protocol just like devices on a home or office network. The OneNet standard was finalized around 2020 after a decade of development, and it aims to complement and extend NMEA 2000, not immediately replace it. In essence, OneNet addresses the limitations of earlier NMEA standards – notably bandwidth and network capacity – while enabling seamless integration with modern IP-based systems and the wider internet.
OneNet provides a common network infrastructure for marine devices and services, carrying the same NMEA 2000 data messages (Parameter Group Numbers, or PGNs) over IPv6 in a standardized format. This allows OneNet networks to share data with NMEA 2000 networks via gateway devices and ensures interoperability with existing marine data formats. In practice, a OneNet network can transport all the familiar navigation and engine data that NMEA 2000 does, but with far greater speed and expansion capability. Furthermore, OneNet is an open industry standard (available to any manufacturer, though the specification must be purchased) and requires certification of devices, similar to NMEA 2000’s certification program. Overall, OneNet is designed to “future-proof” marine electronics by bringing them into the IP era, enabling features like high-speed multimedia data sharing, network security, and integration with cloud or vessel monitoring systems.
Technical Architecture and Protocols
Networking Stack: OneNet operates on the IPv6 protocol suite, meaning each device on a OneNet network is identified by an IPv6 address. Standard TCP/IP networking is supported, but for most NMEA data, OneNet uses UDP datagrams on IPv6 to efficiently broadcast sensor messages (PGN data) without the overhead of TCP connections. These PGN messages are encapsulated in IPv6 packets, allowing traditional NMEA 2000 data to flow over Ethernet with no loss of information. OneNet’s use of IPv6 is forward-looking – IPv4 address space is exhausted, and IPv6 provides virtually unlimited addresses for devices (far more than any vessel would ever need). The IPv6 foundation also facilitates global connectivity; for example, a OneNet device could, in principle, be accessed remotely over the internet (if permitted by security rules), which is a notable shift from the closed, analog nature of past NMEA networks.
High Bandwidth and Data Types: Because it runs on Ethernet, OneNet can support much higher data rates than the CAN-based NMEA 2000 network. A OneNet network can operate at speeds from 100 Mbit/s up to 10 Gbit/s, whereas NMEA 2000 is fixed at 250 kbit/s. This is a 400 to 40,000 times increase in bandwidth, which is transformative for marine data capabilities. It enables transmission of high-bandwidth data types that NMEA 2000 cannot handle – for example, radar imagery, sonar depth sounder scans, live video from onboard cameras, and other data-heavy streams can be carried over OneNet. In the OneNet paradigm, these formerly proprietary or manufacturer-specific Ethernet links (like radar-to-display connections) can become part of the standardized network. The NMEA has plans to standardize new PGNs for such complex data (e.g. video or radar PGNs) so that devices from different makers could potentially share radar images or sonar data over OneNet in an interoperable way. Importantly, OneNet still supports the lower-bandwidth sensor data (GPS, AIS, engine data, etc.) just as NMEA 2000 does – those are encapsulated in the same PGN format over IP. Manufacturers are expected to use NMEA 2000 for basic sensors and OneNet for data-intensive components, with gateways linking the two networks. This dual-network approach leverages the strengths of each: NMEA 2000 for real-time, lower-speed control networks, and OneNet for high-speed, data-rich applications.
Device Discovery and Communication: OneNet implements automatic device and service discovery using standard IPv6 mechanisms. Specifically, it uses multicast DNS (mDNS) and DNS Service Discovery (DNS-SD) for devices to announce themselves and discover each other on the networknmea.org. When a new OneNet device is plugged into the network, it can publish its presence (including information like device name, manufacturer, capabilities, and the data services it provides) so that other equipment or software can find it without manual configuration. This is akin to how a new network printer or IoT device might be discovered automatically in a home network. By contrast, on NMEA 2000 networks, devices use an address-claim process and fixed PGN listings to identify themselves, which is more limited. OneNet’s use of DNS-SD means the network is self-describing and scalable, easing integration of complex systems. Standard IP routing and switching is used, so OneNet devices can communicate across different network segments or VLANs if the network is set up that way – even between vessels or to shore via appropriate routers – something that was impossible with the isolated NMEA 2000 bus.
Security Features: OneNet introduces robust cybersecurity and access control mechanisms that were absent in NMEA 2000. On a OneNet network, all data messages can be encrypted and authenticated. In fact, OneNet specifies that outgoing NMEA data messages should be encrypted, and receiving devices must authenticate the data before using it. This prevents malicious actors from injecting false data or snooping on the network – a growing concern as vessels become more connected. The security model is often compared to a Bluetooth or Wi-Fi pairing process: the boat’s network owner can “pair” devices or applications to the OneNet network using a shared secret (a Master Key), and only those that are authorized can participate. The network owner has control over whether to allow only certified marine devices or also allow consumer devices (like a tablet running a nav app) to connect. For instance, a marine installer could lock down a OneNet backbone so that only NMEA-certified hardware is recognized, or they could permit a third-party app on a tablet to receive data (provided that app has gone through NMEA’s certification). This flexibility means OneNet can be both a closed, secure network for critical systems and an open integration network for innovation – depending on the owner’s preference. These security measures are a significant advancement over NMEA 2000, where any device plugged into the bus can generally read and send data with no authentication. OneNet’s IP-based approach allows standard network security practices (firewalls, encryption, access control lists) to be applied to the marine network, greatly reducing the risk of unauthorized access or data tampering.
PICAN-M – NMEA 0183 & NMEA 2000 HAT For Raspberry Pi With SMPS
The PICAN-M HAT from Copperhill Technologies is a versatile marine communication board designed for the Raspberry Pi, providing seamless integration with both NMEA 0183 and NMEA 2000 networks. Featuring built-in support for the CAN bus via Micro-C connectors and RS422 screw terminals for NMEA 0183, this HAT enables full connectivity with marine instruments and navigation systems.
It includes a wide input power supply (SMPS) that allows the Raspberry Pi to be powered directly from a vessel’s 12V system, simplifying installation. Ideal for use with open-source software like OpenPlotter and Signal K, the PICAN-M turns a Raspberry Pi into a capable and cost-effective marine data hub. More information…
Interoperability and Standards: In designing OneNet, NMEA deliberately leveraged existing internet and industrial standards to ease implementation. The protocol uses many familiar standards (RFCs from the IETF) for things like discovery, transport, and security, rather than inventing entirely new methods. This not only lowers development cost for manufacturers (since off-the-shelf networking stacks can be used) but also ensures OneNet devices can coexist with other IP devices on the same network. OneNet data can travel alongside other services on the boat’s Ethernet network. For example, a boat could have one physical Ethernet network carrying OneNet instrument data, video streams from IP cameras, and even the crew’s internet traffic – all without conflict. The OneNet standard explicitly allows other protocols and services to run in parallel on the same cable/infrastructure. This is a key difference from NMEA 2000: the old CAN-bus is a dedicated link for instrument data only, whereas OneNet converges marine data with mainstream networking. The standard also defines how gateways should operate, enabling connection between a OneNet LAN and an NMEA 2000 backbone (and even other networks like J1939 or older NMEA 0183). These gateways translate NMEA 2000 PGNs to OneNet messages and vice versa, so that a mix of old and new devices can all share information. In short, OneNet adopts a unified networking approach – it brings marine electronics into the realm of IoT and network interoperability, while maintaining backward compatibility through gateways.
Hardware and Implementation Requirements
Implementing OneNet on a vessel involves a different hardware approach than a traditional NMEA 2000 setup. Since OneNet is Ethernet-based, the network topology and components resemble those of standard local area networks:
Cabling and Topology: OneNet networks use Ethernet cabling (typically Cat5e/Cat6 twisted-pair cables for copper, or fiber optic cables for very high speeds or long runs). The network topology is a star or tree architecture using Ethernet switches to interconnect devices, rather than the single-bus topology of NMEA 2000. Each OneNet device is usually connected by an Ethernet patch cable to a central switch (or a daisy-chain of switches). For small installations, a simple marine-grade Ethernet switch with a few ports might serve as the hub of OneNet. Larger vessels can have multiple switches linked together, creating a larger LAN. This inherently allows more flexible layouts than the linear NMEA 2000 backbone (which had strict rules on total cable length and drop lengths). Standard Ethernet range applies – e.g. 100 meters per segment on copper – but fiber uplinks or additional switches can extend the network as needed. OneNet does not mandate special cables beyond the use of industry-standard Ethernet infrastructure, which is advantageous because it leverages widely available technology.
Connectors and Ruggedization: Recognizing the marine environment, OneNet defines specific connector types for different scenarios. The primary OneNet connector for exposed or exterior use is the M12 X-coded Ethernet connector. M12 X-coded connectors are circular, threaded connectors that are waterproof (IP67 or better) and vibration-resistant, commonly used in industrial and marine applications for gigabit Ethernet. They have 8 pins arranged in an X pattern (hence X-coded) and can handle up to 10 Gbps Ethernet. OneNet recommends M12 connectors for deck connections or any place that could be wet or subject to strain, to ensure reliability. For protected areas (interior installations), standard RJ-45 connectors are allowed. Many OneNet devices may simply have an RJ-45 Ethernet jack, identical to those on a home router or PC, if they are intended to be mounted in dry locations. There is even a provision that an RJ-45 can be used in a somewhat exposed location if it’s recessed into a protective cavity or enclosure – but that design must be approved to ensure it provides adequate protection. In practice, we can expect dedicated marine OneNet components (like sensors or displays) to use M12 connectors or sealed RJ-45 ports, whereas an off-the-shelf device like a boat computer or tablet would use a normal RJ-45 or Wi-Fi to join the network. The OneNet standard also anticipates fiber optic connectors for special use cases (e.g., very high bandwidth or long-distance runs, or to eliminate electromagnetic interference). While it doesn’t yet mandate a specific fiber connector, any fiber used must meet generic Ethernet fiber standards (TIA/EIA 568) and future revisions of OneNet may standardize this. Some early adopters in commercial shipping might use fiber backbones for OneNet to cover longer cable runs without loss.
Switches and Network Hardware: To set up OneNet, at least one Ethernet switch is needed on board. This switch functions as the network’s central node, similar to a network hub on larger yachts that might already distribute internet or entertainment data. In fact, existing marine Ethernet switches (used for proprietary networks like Garmin Marine Network or Raymarine SeaTalkHS) can potentially double as OneNet switches if they support the required features. Key capabilities for a OneNet switch include handling IPv6 traffic and multicast properly – most modern switches do this out of the box. NMEA has mentioned “OneNet network services” that switches should support, likely referring to things like Quality of Service (QoS) and prioritization for critical data, as well as possibly IGMP snooping for multicast management (since OneNet devices may broadcast data via IPv6 multicast). While any commercial Ethernet switch will technically forward OneNet data, marine installers may use ruggedized switches that have DC power input and are built to withstand vibration/temperature extremes. Some OneNet-capable switches might come with M12 ports for direct cable connection without adapters (these already exist in industrial automation and can be used in marine contexts). In summary, the hardware backbone of OneNet is very much standard networking gear: Ethernet switches and CAT cables, chosen to marine standards.
Turn Your Raspberry Pi into a Smart Marine Hub with OpenPlotter and Signal K
The world of marine electronics is evolving. Once dominated by expensive, closed systems with limited flexibility, there’s now a shift toward something more open, more personal, and—frankly—more exciting. At the heart of this movement is OpenPlotter, a Linux-based operating system tailored for Raspberry Pi computers, and Signal K, an open data standard designed to bring all your boat’s information together in one place. More information…
Power Over Ethernet (PoE): OneNet leverages PoE to deliver power to devices through the network cable, which is a major advantage in simplifying installations. The standard specifically aligns with IEEE 802.3at (PoE+), allowing up to 25.5 watts of power per device from the switch port. This means that many sensors and even moderate-sized devices (like a compact display or IP camera) could be powered directly via the Ethernet cable, eliminating the need for separate power wiring. By comparison, NMEA 2000’s backbone provides a small amount of 12V power for low-draw devices, but anything requiring more power (like a radar or a large display) cannot be powered from N2K. With OneNet, a high-power device can simply use a PoE-enabled switch port. For example, a future OneNet radar might need only a single Ethernet cable to both power it and receive its data – significantly simplifying the cable runs on a mast. The use of PoE also means that adding more devices is just a matter of having enough PoE switch ports or injectors; you can expand power capacity by adding switches, much like expanding the network itself. Many marine network switches are expected to support PoE out of the box, or installers can use PoE injectors on individual lines if needed. This greater power delivery (25+ watts per port) far exceeds what NMEA 2000 could offer (which typically could supply only on the order of 1–2 watts per device from the backbone in practice). It enables OneNet to support power-hungry gear like multi-sensor modules, cameras, or Wi-Fi access points directly on the network cable.
Device Requirements: Devices that implement OneNet (e.g., sensors, displays, engine interfaces) need more computing resources compared to NMEA 2000 devices. Each OneNet device essentially contains a full network controller and IPv6 stack. In many cases, this means an embedded Linux or similar OS might be running on the device, or at least a microcontroller with a TCP/IP stack and encryption capability. The OneNet standard mandates that each device run the standard IPv6 stack and implement certain required protocols (like the discovery and security protocols). Manufacturers likely have to use more powerful processors and more memory than the tiny microcontrollers often used in simple NMEA 2000 sensors. This is one reason OneNet has been introduced gradually: it’s inherently a bit more complex and expensive to implement. OneNet-certified devices must also go through a testing process to ensure they play nicely on the network and meet compliance (NMEA has a certification tool for OneNet similar to their NMEA 2000 certification suite). From a hardware perspective, a boat owner installing OneNet will find it familiar if they’ve set up computer networks. They will mount an Ethernet switch (or use an existing one), connect devices with Ethernet cables, and possibly configure IP settings or rely on auto-configuration. The network will likely use IPv6 link-local addressing or DHCPv6 to assign addresses automatically. Manufacturers may provide configuration webpages or apps for their OneNet devices (since many run embedded web servers for setup, a common practice with network devices).
Environmental Considerations: Marine conditions (saltwater, vibration, EMI from engines/radars) are always a concern. Fortunately, Ethernet is already widely used in marine environments for other purposes, and OneNet doesn’t introduce unknown hazards. Shielded Ethernet cables and proper grounding will be important to prevent interference, just as with NMEA 2000 cabling. The OneNet Physical Layer specification includes requirements for electromagnetic interference resistance, cable shielding, and even auto-negotiation and auto-MDIX support on the network interfaces. Essentially, OneNet hardware is designed to be as plug-and-play as any modern network, while meeting the tougher electrical and environmental standards of marine electronics.
Comparison with NMEA 2000 (Key Differences and Advantages)
OneNet represents a significant evolution from NMEA 2000. Both standards share the same fundamental goal – seamless data exchange between marine electronics – but they differ drastically in technology and capabilities.
| Feature | OneNet | NMEA 2000 |
|---|---|---|
| Physical Layer | Ethernet (Star/Tree) | CAN (Linear Bus) |
| Bandwidth | 100 Mbps to 10 Gbps | 250 kbps |
| Protocols | IPv6, UDP, TCP | CAN, Proprietary PGNs |
| Security | Authentication, Encryption | None (open broadcast) |
| Device Discovery | DNS-SD, mDNS | Address Claim Process |
| Connector Types | M12 X-coded, RJ-45 | NMEA 2000 Micro-C, Mini |
| Power Distribution | PoE up to 25.5 W | Limited 12V over CAN |
| Multimedia Support | Video, radar, sonar supported | Not supported |
| Max Devices | Thousands (IPv6) | ~50 practical |
Below are the key differences and advantages of OneNet compared to NMEA 2000:
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Data Bandwidth: The most striking difference is bandwidth. NMEA 2000’s CAN-bus runs at 250 kbps (kilobits per second), which has been a bottleneck as marine systems grow more complex. OneNet, running on Ethernet, supports at least 100 Mbps up to 10 Gbps speeds. In practical terms, even a basic OneNet network at 100 Mbit/s is 400 times faster than N2K, and a gigabit link is 4,000 times faster. This huge jump in bandwidth means OneNet can carry large data streams that were impossible over N2K. For example, NMEA 2000 could not transmit things like chart graphics, video feeds, or high-resolution sonar imagery due to size and speed limitations. OneNet easily accommodates these, allowing integration of video cameras, advanced fishfinders, radar, and other high-data sensors on the same network as normal instrument data. The benefit is a unified network – for instance, a single OneNet backbone could handle everything from GPS position updates to live radar scans, whereas previously the radar had to be on a separate proprietary Ethernet. OneNet’s high throughput also means reduced latency for large file transfers or updates (like sharing map updates between devices). In summary, OneNet’s high bandwidth is a game-changer, enabling a level of data richness and fast response that NMEA 2000 could never achieve.
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Network Capacity (Devices and Addresses): NMEA 2000 networks have limitations on how many devices can participate. Officially, an N2K network segment can have up to around 50 physical devices (theoretical address limit is 252, but practical limits are lower due to network load and voltage drop). OneNet, using IPv6, has an enormous addressing space – practically unlimited devices can coexist on a OneNet network (certainly thousands, far beyond any boat’s needs). There is no hard-coded device count limit in OneNet; it’s constrained only by typical network considerations like switch capacity or bandwidth. This allows much larger and more complex networks on bigger vessels or “smart ships.” For example, on a superyacht or commercial ship, you might have hundreds of sensors, actuators, cameras, and user devices connected via OneNet, all addressable and discoverable. Scaling up an NMEA 2000 network beyond a certain point was cumbersome – it required bridging into multiple bus segments and careful bandwidth management. OneNet, by contrast, can be scaled with additional switches and network infrastructure, similar to any enterprise network. The addressing scheme also changes: NMEA 2000 used a dynamic address claiming process for 6-bit addresses (0–251) and relied on 29-bit CAN IDs for messages. OneNet uses 128-bit IPv6 addresses, which can be either auto-configured or static, and standard IP routing if needed. This not only expands capacity but also makes networking more flexible (devices can be on different subnets or even different boats and still exchange data via IP routing or a VPN, which were unheard-of concepts in N2K).
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Data Capacity and PGNs: Along with device count, OneNet effectively removes limitations on message definitions. NMEA 2000 has a finite set of PGNs defined (on the order of a few hundred standardized PGNs, plus some proprietary ranges). While this was already quite extensive, adding new PGNs under N2K required updates to the standard and careful allocation because of the limited ID space. In OneNet, because it’s not constrained by CAN message ID bits, the PGN identifier is carried in an IPv6 extension header and can be much larger if needed. The standard notes that OneNet has no real limit on the number of PGNs or types of data it can support. This means as new technologies emerge (e.g., new sensor types, or future navigation data types), OneNet can incorporate them more readily. Additionally, the size of a single message in OneNet can be much larger than on N2K – a OneNet UDP datagram can carry kilobytes of data if needed. By contrast, NMEA 2000 frames can carry at most 8 bytes per CAN frame, and even using multi-packet PGNs, large messages are inefficient. OneNet can send a photo or a radar sweep in a single or a few packets, dramatically increasing efficiency for large transfers.
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Physical Layer and Topology: NMEA 2000’s physical layer is a powered CAN bus (a single shared backbone cable with drop cables to each device). It’s a one-to-all broadcast bus where every device sees all messages and the bus arbitrates access. OneNet uses the Ethernet physical layer – a switched network where each link is point-to-point between a device and a switch. This confers several advantages. Firstly, Ethernet switches manage traffic so that messages are forwarded only to the intended recipient (or to the whole network if using multicast/broadcast), which reduces unnecessary load on devices. Secondly, the star topology allows easier incremental expansion: adding a new device doesn’t electrically load down a backbone or require thinking about drop line lengths; you just plug it into a switch (or add another switch). Fault isolation is also better – a failure of one cable or port typically doesn’t bring down the entire network, unlike a backbone break in N2K which could disable the network segment. On the downside, OneNet’s reliance on switches means a bit more hardware (and power draw) is required, whereas an N2K backbone is passive. However, modern switches are quite reliable, and redundancy can be introduced by interconnecting switches if needed. OneNet’s tolerance for long runs is better too (100m per hop on copper, and much more with fiber), whereas N2K had strict limits (~200m total backbone length without repeaters). In terms of connectors, as mentioned, OneNet adopts Ethernet connectors (RJ45, M12) which are physically different from NMEA 2000’s multi-pin circular connectors. The advantage is that Ethernet cables and connectors are ubiquitous and can carry power (PoE), whereas N2K cables are a specialized standard that carry limited power. That said, NMEA 2000 cables and connectors are very robust and standardized for marine use, so OneNet’s introduction of multiple connector types might create some initial confusion or need for adapters on boats (for instance, adapting an M12 device to a switch with RJ45 ports via a cable).
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Power Distribution: NMEA 2000 combines data and power on the same cable, delivering typically 12 V DC (with a max current of a few amps for the whole backbone) to run small electronics. This is convenient for tiny sensors, but insufficient for larger devices. OneNet, by using Power over Ethernet, can deliver up to 25.5 W per device over the network. This is a huge advantage for installation flexibility. It means even medium-sized devices (like a touchscreen display, a weather sensor suite with heaters, or a Wi-Fi access point) might be powered by the network cable. High-power devices (say a radar that needs 50+ W) would still have separate power, but those are a minority. The result is a cleaner installation – a single cable can often replace the separate power and data cabling of older systems. This is beneficial for retrofits and new builds alike. Additionally, OneNet’s power delivery is managed by standard PoE negotiation, so a switch will only supply power if the device requests it, preventing misuse and providing some protection (N2K required manual calculation of load and fuse sizing to ensure the backbone wasn’t overdrawn). OneNet can thus simplify wiring and reduce weight on larger vessels by consolidating cables.
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Interoperability and Data Sharing: NMEA 2000 was a big step up from the one-sentence-at-a-time NMEA 0183, allowing multi-talk/multi-listen on a network. However, N2K still effectively created isolated “islands” of network – bridging to other networks or to the internet required translation devices. OneNet, being IP-based, merges the marine network with general networking. This has several implications. One is that marine data can be more readily shared with non-marine systems: for example, sending navigation data to a ship’s IT network or to an internet connection for remote monitoring becomes straightforward. Another implication is that manufacturers can more easily develop software applications (for PC, smartphone, etc.) that interface with OneNet data, since they can use standard networking APIs rather than proprietary CAN interfaces. We are likely to see more apps and PC-based tools that connect to OneNet for vessel data, because joining a OneNet network is as simple as plugging into an Ethernet jack or connecting via Wi-Fi (if bridged) and speaking the OneNet protocol. This was harder with N2K, which needed specialized hardware adapters and proprietary libraries to parse PGNs. OneNet also promises better multi-vendor interoperability. While NMEA 2000 is itself an interoperable standard, in practice many manufacturers kept certain high-end functions (like radar or chart sharing) proprietary. OneNet opens the door for those functions to be standardized. For example, previously a radar from Manufacturer A could usually only display on Manufacturer A’s MFD over a proprietary Ethernet link. With OneNet, if a common radar protocol is agreed upon, a third-party display could potentially use any OneNet radar. Even if that level of openness is slow to come, OneNet at least makes basic data sharing across brands easier, because everything is on one IP network. The addressing and discovery improvements also mean that adding a device from a new manufacturer should be less of a hassle – it announces itself and is accessible if certified, whereas on N2K one often had to ensure proprietary PGNs were supported or consult documentation to know what data is being output.
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Network Management and Security: As mentioned, OneNet introduces encryption and network access control. This directly addresses a weakness of NMEA 2000, which had no security (anyone who could tap into the network could inject or read data). On a OneNet system, a boat can be more safely opened up for remote access or cloud connectivity because the owner can enforce security policies. For example, a yacht operator could allow an authorized shore service to log in over the internet to the OneNet network for diagnostics, without fear of eavesdropping or unauthorized control, thanks to encryption and authentication handshakes. Additionally, standard IT network management tools can be used on OneNet: firewalls to segment the network (perhaps navigation vs entertainment devices), VLANs to prioritize critical data, and monitoring tools to log network traffic. This level of management is far beyond N2K, where at best one could use an N2K analyzer tool to see messages. The advantage here is especially important for larger vessels or commercial ships, where cybersecurity is a serious concern and integration with enterprise systems (like voyage data recorders or telematics) is needed. OneNet essentially elevates marine electronics to be first-class citizens in the IT domain, allowing professional management and security practices. The trade-off is increased complexity – small boat owners and installers may need to acquire some networking knowledge (IP addresses, switch configuration) which was not needed for N2K plug-and-play. However, the NMEA has tried to keep OneNet as plug-and-play as possible by using automatic discovery and configuration where feasible. Over time, as OneNet equipment becomes common, it’s likely that the user experience will be streamlined by manufacturers (for instance, MFDs might show a list of OneNet devices on the network and handle the behind-the-scenes IP configuration automatically).
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Real-Time Performance: One area where NMEA 2000 still holds an edge is in real-time determinism for critical control data. The CAN bus protocol in N2K guarantees a message arbitration and prioritization at the hardware level – higher-priority messages (like safety-related data) can preempt lower ones, and the worst-case latency is bounded and very low (a few milliseconds). Ethernet and IP, by default, do not guarantee delivery times; they work on a “best effort” basis. In a lightly loaded OneNet, latency will also be very low (sub-millisecond switching delays), but if the network is busy or poorly configured, delays or even packet loss can occur. For this reason, NMEA has indicated that OneNet is not intended for hard real-time control loops – for example, you wouldn’t want a critical engine cutoff command to rely solely on an IP network without careful design. NMEA 2000 (or directly wired systems) may still be used for time-critical controls like throttle-by-wire, steering, or emergency stop, where absolute reliability and minimal latency are paramount. OneNet’s role would be to carry less time-sensitive or high-bandwidth data (monitoring, sensor fusion, user interface data, etc.). That said, Ethernet can be made near-deterministic with proper use of quality-of-service and perhaps Time-Sensitive Networking (TSN) standards in the future. As OneNet matures, we may see it taking on more of these tasks. For now, an advantage of OneNet is that it can concentrate heavy data flows off the N2K bus, relieving the load on NMEA 2000. A current best practice is likely to use N2K for core sensor data and engine info, and use OneNet for things like sonar feeds, multiple video cameras, or sharing detailed chart data between systems. The two networks can be linked by a gateway, ensuring all essential data is mirrored across, but each network handles the data types it’s best suited for.
In summary, OneNet’s advantages over NMEA 2000 include vastly higher speed, more expandability, better power distribution, modern networking features, and built-in security. NMEA 2000, on the other hand, remains a proven, simple, and robust solution for basic instrument networking with minimal configuration. For the marine industry, OneNet and NMEA 2000 will coexist: NMEA 2000 still excels for small sensors and minimal infrastructure, whereas OneNet shines in data-heavy, integrated systems. Many boats will likely end up with a hybrid: a OneNet backbone tying together high-end gear and various sub-networks, and an N2K backbone for legacy devices or simple sensors, with a gateway between them. OneNet truly extends the concept of the “networked boat” to encompass everything on board, operating more like an enterprise network or a shipboard LAN, which is a leap forward in capability.
Adoption Status and Industry Usage
As of 2025, OneNet is in the early stages of adoption within the marine industry. The standard itself was officially released as NMEA OneNet Version 1.0 in late 2020, but it typically takes a few years for manufacturers to develop and certify products under a new standard. Indeed, the first OneNet-certified product was not announced until mid-2024: Airmar’s SmartBoat® module achieved the world’s first OneNet certification in July 2024. Airmar’s SmartBoat is a vessel monitoring and control system that acts as a bridge for multiple standards – it interfaces with NMEA 0183, NMEA 2000, and now OneNet, linking all types of sensors into one system. The fact that the first certified device is a multi-network gateway is telling: it highlights the industry’s approach of gradual integration, where OneNet is added alongside existing networks. Airmar’s achievement was seen as a milestone demonstrating OneNet’s viability in a commercial product. The SmartBoat system benefits from OneNet by gaining faster data exchange and easier integration with IP-based systems (for instance, it can funnel boat data to a computer or cloud service using standard networking). Following Airmar, other companies have been preparing OneNet-capable products. For example, some marine electronics manufacturers in Asia, like ONWA, have indicated that their latest chartplotters will support OneNet networking (their new KM series was reported to include OneNet connectivity via Ethernet ports). This suggests that smaller or agile companies are starting to embrace the standard, potentially to gain a technological edge.
Teensy 4.0 NMEA 2000 Simulator
The NMEA 2000 Simulator is a versatile tool for developers and technicians working with marine electronics. At its core, it utilizes the powerful Teensy 4.0 microcontroller, which comes pre-installed and pre-programmed with specialized simulator firmware. This compact, bench-top device is ideal for testing NMEA 2000-compatible equipment without requiring live data from an actual vessel.
By simulating real-world marine conditions and sensor outputs, the device allows for comprehensive diagnostics, validation, and troubleshooting of marine electronics such as chartplotters, engine monitors, and autopilot systems. It is particularly useful in R&D labs, product demonstrations, and technical support environments. More information…
Major marine electronics brands (Garmin, Navico/Simrad/B&G, Raymarine, Furuno) have been more cautious publicly, as they each have proprietary Ethernet networks in their current product lines. However, behind the scenes, all these manufacturers were involved in the OneNet development committee and are likely working on OneNet compatibility. It is expected that multi-function displays (MFDs) and chartplotters will be among the first mainstream devices to get OneNet features, since many high-end MFDs already have Ethernet ports (for radar, sonar, or video integration). Enabling OneNet on an existing Ethernet-equipped MFD could be as simple as a software update in some cases. Industry observers predicted that the first chartplotters with OneNet support would appear soon after the standard release, given that the hardware was largely in place. While adoption was a bit slower than initially hoped (2020 saw no big OneNet product launch, partly due to tool development and possibly the pandemic impacts), by 2024–2025 we’re finally seeing movement. It wouldn’t be surprising if by late 2025 or 2026, one of the major brands announces that their next-gen marine network will be “OneNet-based” or OneNet-compatible. In fact, there are hints: for instance, some forum reports suggest Garmin has been developing a new marine network connector (dubbed “BlueNet”) which is essentially a variant of the OneNet M12 connector standard, implying OneNet or a similar Ethernet protocol is on their radar for future products.
Early use cases for OneNet in 2025 include high-bandwidth sensor integration and vessel data management. Forward-looking boat builders and tech-savvy yacht owners are interested in OneNet to handle things like multiple IP cameras on board (for security and monitoring), high-definition sonar imaging systems, and advanced engine monitoring that outputs large data streams. With OneNet, all these can feed into the main network and be accessible from any station on the vessel, or even remotely. For example, a sportfishing yacht could have a OneNet network where live video from underwater cameras, detailed fishfinder data, and navigation info all converge and can be displayed on any connected screen or streamed off the boat. Commercial vessels (like research ships or workboats) find OneNet appealing for its capacity to carry scientific data or detailed equipment diagnostics over the same network that carries navigation data. OneNet is also attractive for the emerging trend of integrated vessel management systems – essentially the “glass cockpit” concept in boating – where every system from engines to air conditioning to navigation can be monitored and controlled centrally. The high bandwidth and device capacity of OneNet make it possible to have a single network backbone for these disparate systems.
Current adoption status can be summarized as early adoption and trials. Besides Airmar, we have seen a OneNet software stack (called Aeolus-One) get certified. Aeolus-One is a OneNet protocol stack for general computing platforms (Linux, Windows, etc.), which indicates that software developers are gearing up to create OneNet-compatible applications for PCs and mobile devices. This is important because it means we might soon have marine charting apps or vessel monitoring apps that speak OneNet natively, allowing a tablet or laptop to plug into the network and directly exchange NMEA data without any gateways. The NMEA itself provided a OneNet Certification Tool to manufacturers (listed as an official product in 2024), which has facilitated companies in testing their devices for compliance. The pipeline likely contains more OneNet devices: rumors include OneNet-capable weather sensors, engine gateways, and even radios. However, as an industry, the transition is cautious. Many manufacturers are ensuring that OneNet products will also interface with NMEA 2000 (to protect customers’ existing investments). So early OneNet devices are often dual-network: for example, a wind sensor might output NMEA 2000 on one port and OneNet on another, or a gateway might serve as a bridge. This dual compatibility is seen as essential during the phase-in period.
The marine industry is historically slow in adopting new standards, but there is consensus that OneNet is the future foundation. The NMEA 2000 standard itself took years to gain dominance after its early-2000s introduction – it wasn’t until the 2010s that N2K became ubiquitous on recreational boats. By analogy, OneNet’s wider adoption will likely ramp up through the mid and late 2020s. A positive sign is that OneNet aligns with general technology trends (IoT, network integration), so it has more pull than NMEA 2000 did in its early days. Moreover, OneNet doesn’t necessarily require all-new cabling on many boats: if a vessel already has an Ethernet network for entertainment or proprietary links, that infrastructure can potentially carry OneNet traffic with a firmware update or minor tweaks. Some modern boats already come with an IP network for cameras or Wi-Fi; those could double as the OneNet backbone, making adoption easier. We are also seeing interest from the boating community: discussions on forums show that tech-minded boaters are asking when they can get OneNet equipment, and some are even critical of NMEA for the slow rollout. This demand pressure will likely encourage the big marine electronics brands to introduce OneNet in upcoming product lines to stay competitive.
In terms of real-world use (as of 2025), OneNet is not yet a common sight on the average sailboat or powerboat. Most remain on NMEA 2000 networks. However, early deployments are happening in larger yachts and commercial vessels, often in a limited capacity. For instance, a new superyacht might install a OneNet network primarily to handle an IP camera system and high-speed internet distribution on board, and then also use it to gather NMEA 2000 data via a gateway – essentially laying the groundwork for a full OneNet system as more devices become available. Some marine electronics installers are starting to advertise OneNet readiness, acknowledging that if owners plan to keep a boat for 10-20 years, a OneNet infrastructure now could accommodate future upgrades.
The marine industry organizations are also actively promoting OneNet. The NMEA holds workshops and training for OneNet, ensuring installers and developers become familiar with it. The standard has been presented at conferences since 2019, and by 2022–2023 the NMEA even introduced a related concept called NMEA Cloud Services for off-vessel data exchange, which complements OneNet’s on-vessel networking. This indicates that the vision is a fully networked boat connected to cloud systems – and OneNet is the enabling technology on the boat side.
To summarize the adoption status: OneNet is at a nascent but growing stage. The first certified devices (hardware and software) emerged around 2024, and more are expected in the immediate future. The technology promises clear advantages and is likely to be standard on new high-end vessels within a few years. For now, it coexists with NMEA 2000, which remains in widespread use. As more OneNet-certified sensors, displays, and integration modules hit the market, we can expect a tipping point where new boats start being built with OneNet as the primary network and N2K mainly for legacy support. The marine electronics community is watching closely, as OneNet has the potential to unify currently fragmented systems and significantly enhance how marine data is used and shared.
Conclusion
OneNet represents a pivotal advancement in marine networking, bringing the industry in line with modern communication technologies. Technically, it transforms the boat’s data network into an IP-based, high-speed LAN, capable of carrying everything from simple sensor readings to streaming video. Practically, it offers boaters and manufacturers a new level of interoperability, scalability, and integration with the wider digital world. While NMEA 2000 remains reliable for core functions, OneNet opens the door to new applications and efficiencies – greater volumes of data, plug-and-play device discovery, network-powered devices, and cybersecurity features to protect critical systems. The transition is just beginning, but the benefits of OneNet are clear. As adoption grows, the marine industry will likely see an ecosystem of OneNet devices and software that greatly improves how we manage and monitor vessels. In time, a OneNet network may be as standard on boats as NMEA 2000 networks are today, enabling a truly integrated “smart boat” where all electronic systems communicate seamlessly. For anyone planning the electronics of a new vessel or an upgrade, OneNet is an important development to keep in view, promising to future-proof the vessel for the data demands of the coming decades.
References
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National Marine Electronics Association – OneNet Overview:
https://www.nmea.org/content/STANDARDS/OneNet.aspx -
AIRMAR’s OneNet Certification Announcement (July 2024):
https://www.airmar.com/news/oneNet_certification.html -
Actisense – Guide to NMEA 2000 and OneNet:
https://www.actisense.com/knowledge-base/nmea-2000-vs-onenet/ -
NMEA Press Release – OneNet v1.000 Standard Release (Dec 2020):
https://www.nmea.org/Assets/nmea_onenet_standard_release_dec2020.pdf -
Aeolus-One Protocol Stack Certification Announcement:
https://www.nmea.org/news/aeolus-onenet-stack-certified -
Digital Yacht – Understanding NMEA Protocols:
https://digitalyacht.net/2021/06/07/nmea-0183-nmea-2000-and-nmea-onenet/ -
NMEA OneNet Certified Product List (2025):
https://www.nmea.org/products/onenet-certified-products
When you’re miles from shore, the last thing you need is trouble with your boat’s electrical or electronic systems. In Advanced Marine Electrics and Electronics Troubleshooting, marine technology expert Edwin Sherman demystifies the complex, interconnected systems found on today’s vessels.
This comprehensive guide—rich with practical charts, diagrams, and real-world advice—is an essential resource for both professional marine technicians and hands-on boat owners. Inside, you’ll learn how to:
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Detect and resolve stray current issues and galvanic corrosion
Whether you’re servicing a cruising yacht or maintaining your weekend sailboat, this book provides the knowledge and skills to keep your onboard systems running reliably and safely. More information…
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