AIS ATB1 Class B+ AIS Transceiver

The Ocean Signal ATB1 Class B+ AIS Transceiver incorporating the superior SOTDMA access scheme provides increased visibility and safety at sea.

The fully compliant ATB1 Class B+ (SOTDMA) AIS Transceiver from Ocean Signal is the latest in a long line of essential sea-safety equipment developed and manufactured in the UK for the Maritime market.

Designed as an aid to collision-avoidance, it provides a significant advantage in navigational safety giving you the peace of mind that your vessel will be seen day or night, no matter the weather, on today’s busy waterways.

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SKU: 762S-02700

Categories: Discontinued

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Increased visibility to other vessels (SOTDMA)

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FREE user-friendly mobile app for set up

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WiFi, USB, NMEA 0183 and NMEA 2000®

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Simple to install and use

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Superior internal 99 channel GPS receiver

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Supplied with external mount GPS antenna

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There are Firmware Updates available for this product

The ATB1 needs to be configured by the user to enter the vessels MMSI number and other details.
This can be carried out by a mobile App or a web based program, please select Product Programming link below product name to start configuring.



Your vessel information such as position, speed, course and heading is ascertained automatically and continuously using the impressive internal multi-GPS receiver for accurate global positioning. Boasting 99 acquisition channels and 33 tracking channels, this advanced technology ensures that the AIS transmissions provide the most accurate indication of your vessel’s position at all times.


Other vessel information such as vessel name, call sign, type and dimensions as well as the MMSI are also transmitted automatically from the ATB1. This information is uploaded to the ATB1 via WiFi directly from Ocean Signal’s user-friendly mobile app or website. Once this information has been uploaded, it remains stored in the unit’s non-volatile memory even if powered down for long periods of time.


The ATB1 also receives and interprets AIS messages from other AIS equipped vessels within range, which can then be relayed effortlessly to other navigation devices such as chart plotters, laptops or mobiles using the ATB1’s NMEA 0183, NMEA 2000®, USB or WiFi outputs.


Using the superior SOTDMA* access scheme sets the ATB1 apart from the CSTDMA** class B products available. This Ocean Signal Class B+ unit has the same AIS transmission priority as a class A unit, giving the added assurance that there will be no loss or delay of transmission, even in high traffic areas.


The ATB1 also has a faster reporting rate and higher output power than CSTDMA class B units.  It sends AIS transmissions every 5 seconds instead of the maximum two transmissions per minute and the 5W output power instead of 2W allows your transmissions to reach further.


A multi-colour LED indicator light on the ATB1 signals the on-going operational status of the unit. This additional safety feature provides you the confidence of knowing that the ATB1 has continuous AIS transmission and optimal performance. The ATB1 has a sleek yet rugged waterproof design that is high on performance and low on energy consumption. 


It is quick and simple to install and comes complete with an external GPS antenna, meaning that all you need is the use of a suitable device (mobile phone, tablet or PC) to upload your vessel information, and you can begin transmitting your AIS messages within minutes.


A leader in life-saving maritime products for the professional and leisure markets, Ocean Signal yet again provides the ultimate in safety and peace of mind with the ATB1 Class B Transceiver.


* Self Organised Time Division Multiple Access
** Carrier Sense Time Division Multiple Access


For ATB1 firmware updates and the revision history please see this page.


Transmit Power

5/1 Watts

Frequency Range

156.025 – 162.025 MHz

AIS Modulation

GMSK: BT 0.4



-107 dBm for 20% packet error rate

Frequency Range AIS RX1 & RX2

156.025 – 162.025 MHz

Frequency DSC



Temperature Range

-15°C to +55°C / 5°F to 131°F


IPx7 (1 metre for 30 minutes)

Supply Voltage Range

10.8 V to 31.2 V

GPS Receiver


High Sensitivity


99 acquisition / 33 tracking


Serial ports

IEC61162-1, -2 (NMEA 0183); 2 Rx/Tx / NMEA2000® / USB / WiFi IEC802.11 bgn



IEC62287-2, IEC60945

Your Ocean Signal product is warranted against manufacturing defects in materials and workmanship for a period of 2 years from the date of purchase and in accordance with the following conditions.


Ocean Signal will at its discretion, repair or replace faulty product free of charge excluding the cost of shipping. Proof of purchase from the original purchaser shall be required in order for a warranty claim to be valid. All claims shall be made in writing to Ocean Signal or an approved service dealer or


Ocean Signal shall not be liable to the buyer under the above warranty:


  • for any repairs or modifications carried out on the product using parts that are not supplied
    or approved by the manufacturer Ocean Signal including batteries and for work carried out
    other than by Ocean Signal or approved service dealers,
  • for any part, material or accessory that is not manufactured by Ocean Signal, the consumer
    will be covered by the guarantee / warranty offered to Ocean Signal by the manufacturer or
    supplier of such a component,
  • for product which has not been fully paid for,
  • for any product supplied by Ocean Signal to a customer under an alternative warranty or
    commercial agreement,
  • for the cost of shipping product to and from the customer.


The following specific item is excluded from this warranty:


  • Damage to the antenna


This warranty does not affect your statutory rights.


Extended Warranty


By entering your product details you can add 3 years to the warranty period.

What information is transmitted?

Position reports (MMSI, Lat, Long, COG, SOG) for Class B (SOTDMA)

  • Every 3mins. when SOG < 2 knots
  • Every 30s when SOG >= 2 knots < 14 knots
  • Every 15s when SOG >= 14 knots < 23 knots
  • Every 5s when SOG > 23 knots

Vessel data (Name, call sign, dimensions, type etc.)

  • Every 6mins.

This means that if you are moored or in the marina your data may take some while to be visible on other peoples systems.
Depending on your location visibility on Marine Traffic or Shipfinder websites may take much longer.

Can I use an existing GPS receiver or GPS data instead of installing an additional GPS antenna for the AIS?

No. The use of the internal GPS receiver is a requirement of the AIS regulations.

The AIS can be used as a position source output by configuring it to output GPS position data (RMC NMEA sentence) although this is not generally recommended.

Can I change the MMSI or vessel details?

Always take great care when entering the MMSI number.
Once programmed changing the MMSI number will require the AIS to be ‘unlocked’ by contacting Ocean Signal via the set-up app. This could take up to 2 days.

Changing all other details entered is simple using the Mobile or Web based set-up app’s.

What type of radio antenna should I use ?

The ATB1 transmits and receives on the VHF band so any good quality Broad Band Marine VHF antenna will be suitable.

There are AIS Tuned antennas available which are suitable but other narrow band or tuned antennas should be avoided. If a single antenna is to be used by VHF radio and an ATB1 then an active antenna splitter should be installed.

What is the range of AIS?

This varies enormously depending on weather, VHF antenna height etc.

  • Typical transmit range for Class B is 10nm
  • Typical receive range for Class A targets is 20nm
  • Receive range can exceed 100nm in the right conditions

How do I configure my ATB1?

The ATB1 needs to be configured by the user to enter the vessels MMSI number and other vessel details.
This can be carried out by a mobile App or a web based program:

  • For the Mobile Android version search the Playstore for Ocean Signal
  • For the Mobile iOS vesion – this version is coming soon
  • For the Web version click here

How it Works – AIS Factsheets

Written by Ocean Signal’s Technical Business Development Manager Kris Nieuwenhuis
here are some interesting and useful documents explaining various aspects of an AIS system
and how the extended features work to add value to your product:

My Android phone/tablet will not connect to my AIS?

My Android phone/tablet will not connect to my AIS?

Users of Android 10+ Operating System on some mobile devices may encounter connectivity issues when using WiFi due to a change in the way that they now interact with WiFi networks.

Whilst the majority of devices are not affected by this change, some product ranges are unable to support certain applications requiring WiFi connectivity, including the Ocean Signal AIS Config app.

Ocean Signal have no control over these WiFi connectivity issues and therefore we are unable to resolve this for any of our customers.

Workarounds for you to use if no solution for your mobile device is available:

  • The AIS configuration of the Ocean Signal product must be performed using an alternative mobile device; or
  • Use the WEB app and a USB stick file created on:

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