AIS — Automatic Identification System — is what lets nearby vessels, port authorities and coastal stations see who you are, where you're heading and how fast you're moving, all without a single radio call. It works alongside radar rather than replacing it: radar tells you something is there, AIS tells you what it is. For fleet operators and repair yards, understanding the difference between Class A and Class B units is the first thing to get right before ordering.
What AIS Actually Broadcasts
An AIS transponder sends out two types of data on a continuous cycle: static information (vessel name, dimensions, call sign) and dynamic information (position, course, speed, rate of turn) pulled from the GPS and gyrocompass feed. Nearby vessels and shore stations receive this automatically, which is why AIS has become such a core tool for collision avoidance in busy shipping lanes.
Class A vs Class B: The Core Difference
- Class A: higher transmission power, faster reporting rate (as often as every 2 seconds when manoeuvring), and broadcasts a wider set of voyage data. This is the standard fitted on merchant vessels, tankers and larger commercial ships.
- Class B: lower power, slower reporting rate, and a lighter data set. Typically used on smaller craft, support vessels and workboats where full Class A capability isn't required.
Mixing up the two is a common mistake — a vessel that needs Class A carriage cannot simply substitute a Class B unit to save cost, since the reporting rate and data output don't meet the same operational standard.
Integration With Radar and ECDIS
Most modern bridges overlay AIS targets directly onto the radar or ECDIS display, correlating a radar contact with its AIS identity automatically. This target correlation is one of the biggest practical benefits of AIS — it turns an anonymous radar blip into a named, tracked vessel with known course and speed. Before ordering a transponder, confirm its output format is compatible with the radar and ECDIS units already on the bridge.
Antenna Placement Matters
AIS transmission range depends heavily on antenna height and placement, not just transceiver power. A poorly sited antenna — blocked by superstructure or mounted too low — can noticeably shrink the effective range even on a high-power Class A unit. This is worth checking during any new installation or refit rather than assuming range will match the spec sheet.
AIS Transponder Brands & Model Numbers We Work With
Most vessels we support are already running one of a handful of established AIS brands. Here's a quick reference on the model numbers you're likely to come across, and what each is generally used for. Nautical Marine Services supplies units across all of these brands on an order basis — see our full AIS transponder range.
Furuno
| Model | Notes |
|---|---|
| Furuno FA-150 | Class A transponder, standard commercial vessel fit |
| Furuno FA-170 | Class A transponder, 4.3" colour display, storage for over 2,000 AIS targets |
| Furuno FA-30 | Class B transponder/receiver, lighter-duty applications |
| Furuno FA-40 | Class B transponder/receiver |
| Furuno FA-50 | Class B transponder/receiver |
| Furuno FA-70 | Class B transponder/receiver, smaller-vessel applications |
Furuno FA-150 & FA-170
Looking for the Furuno FA-150 specification? This is a Class A transponder built for standard commercial vessel fit. We can confirm current FA-170 price and its 2,000-target storage capacity on request.
Furuno FA-30, FA-40, FA-50 & FA-70
These are Furuno's Class B transponder/receiver models for lighter-duty and smaller-vessel applications. Ask us for the current FA-30 price, or to confirm the FA-40/FA-50/FA-70 specification for your vessel.
Looking to buy or replace a Furuno AIS transponder? Send us your model number — we confirm current specification, price and lead time before you order.
JRC (Japan Radio Co.)
| Model | Notes |
|---|---|
| JRC JHS-182 | Class A transponder, long-range reception, compact display unit |
| JRC JHS-183 | Class A transponder, newer of the two with an updated internal design |
JRC JHS-182 & JHS-183
Looking for the JRC JHS-182 specification? This Class A transponder offers long-range reception in a compact display unit. We can confirm current JHS-183 price and availability for your vessel.
Looking to buy or replace a JRC AIS transponder? Send us your model number — we confirm current specification, price and availability before you order.
Koden
| Model | Notes |
|---|---|
| Koden KAT-3300 | Class A transponder, dual-channel tracking, built-in Wi-Fi for fleet-level monitoring |
Koden KAT-3300
Looking for the Koden KAT-3300 specification? This Class A transponder offers dual-channel tracking with built-in Wi-Fi for fleet-level monitoring. Contact us for current price and availability.
Jotron
| Model | Notes |
|---|---|
| Jotron Tron AIS TR-8000 MkII | Class A transponder, separate transceiver and 7" touchscreen display, Ethernet-connected, current replacement for the original TR-8000 |
Jotron Tron AIS TR-8000 MkII
Looking for the Jotron TR-8000 MkII specification? This Class A transponder is the current replacement for the original TR-8000, with a separate transceiver and 7" touchscreen display. We can confirm current price and availability.
Saab (TransponderTech)
| Model | Notes |
|---|---|
| Saab R4 AIS | Fourth-generation Class A transponder, in service on a large share of the world's commercial fleet |
| Saab R5 SUPREME AIS | Fifth-generation Class A transponder, large colour touchscreen display, built for integrated bridge systems |
| Saab R5 SOLID AIS | Fifth-generation Class A transponder, based on the same platform as the R5 SUPREME |
Saab R4 AIS
Looking for the Saab R4 AIS specification? This fourth-generation Class A transponder is in service on a large share of the world's commercial fleet. We can confirm current price and spare parts availability.
Saab R5 SUPREME & R5 SOLID AIS
The Saab R5 SUPREME AIS and R5 SOLID AIS are fifth-generation Class A transponders built on the same platform for integrated bridge systems. Ask us for current price and availability on either model.
Looking to buy or replace a Saab AIS transponder? Send us your model number — we confirm current specification, price and availability before you order.
Sperry Marine (Northrop Grumman)
Sperry Marine's AIS transponders integrate directly with VisionMaster bridge systems, sharing target data across radar and ECDIS displays without a separate standalone unit cluttering the bridge layout.
Frequently Asked Questions – AIS Transponder Models
What is the Furuno FA-150 specification?
The FA-150 is Furuno's Class A transponder built for standard commercial vessel fit. Contact us for the full specification sheet, current price and lead time.
Where can I buy a Furuno FA-170 or spare parts?
We supply the FA-170 and its spare parts to order. Send us your vessel type to confirm current availability and price.
What is the difference between JRC JHS-182 and JHS-183?
Both are Class A transponders with long-range reception; the JHS-183 is the newer of the two with an updated internal design. We can confirm which fits your vessel's setup.
Does the Koden KAT-3300 support fleet-level monitoring?
Yes — the KAT-3300 includes built-in Wi-Fi and dual-channel tracking, making it suited to fleet-level monitoring alongside standard Class A carriage.
Is the original Jotron TR-8000 still available, or only the MkII?
The Tron AIS TR-8000 MkII is the current replacement for the original TR-8000. We can confirm current availability and help with the upgrade path if your vessel is still running the original unit.
What is the current Saab R5 SUPREME AIS price?
Pricing depends on configuration and bridge integration requirements. Send us your vessel details for an accurate quote on the R5 SUPREME or R5 SOLID.
How do I identify which AIS transponder model my vessel is running?
A photo of the transponder unit and display nameplate is usually enough for us to confirm the exact model and current availability.
Quick Checklist Before You Order
- Confirm whether the vessel requires Class A or Class B carriage
- Check GPS feed accuracy and antenna condition before installation
- Verify output format matches existing radar/ECDIS overlay
- Plan antenna placement for maximum unobstructed range
Once you've confirmed your specification, Nautical Marine Services can check availability from our AIS transponder range and arrange delivery to your vessel's next port of call.
Need an AIS Transponder for Your Vessel?
Nautical Marine Services works on an order basis — share your vessel class and operating area, and we'll help you supply the right AIS unit from our AIS transponder range for delivery to your vessel.
Request a QuoteRelated Reading
Marine Radar Systems: A Buyer's Guide
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