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Manufacture of Sonardyne ‘AODC’ Diving Bell Emergency Transponders Discontinued

  1. Background

Sonardyne International Ltd has recently announced the obsolescence of its types 7097 & 7192 Diving Bell Emergency Transponders.  These were often referred to as the Sonardyne ‘AODC emergency transponders.’  

Today, the requirement for emergency locating devices to be fitted to diving bells is mandated within the IMO Code of Safety for Diving Systems 1995 and there is clearly a continuing need for properly specified locating devices to be fitted to diving bells. 

This Information Note is intended to:

  • make IMCA Diving Division Members aware of the discontinuation of the Sonardyne products;
  • draw Members’ attention to Sonardyne Technical Bulletin No. TB21-001 (Issue 01) RJE ATT400 AODC Transponder Compatibility (dated 12th January 2021), which directs users of the discontinued Sonardyne transponders to the supplier of an equivalent alternative system which has been identified and tested by Sonardyne; and
  • alleviate the concerns of diving contractors with respect to the continuing availability of suitable diving bell locating devices.

2. Current IMO Requirements

Paragraph 2.12.5 of the IMO Code of Safety for Diving Systems 1995 sets the requirements for diving bell emergency locating devices i.e. the diving bell emergency transponder and the diver-held interrogator receiver. 

Copies of the Code may be purchased from IMO using the following link: Publications (

3. Continuing Availability of Suitable Diving Bell Locating Devices

Sonardyne advises that it has identified and tested a suitable transponder from an alternate supplier that meets the IMO requirements and is compatible with Sonardyne’s Ultra-Short BaseLine (USBL) underwater target tracking systems.  Please see Sonardyne Technical Bulletin No. TB21-001 (Issue 01) attached as Appendix 1 for details.
For more information, please contact Sonardyne International Ltd at: 

Sonardyne International Limited Blackbushe Business Park Yateley, Hampshire GU46 6GD United KingdomT. +44 (0) 1252 872288 F. +44 (0) 1252 876100 E. [email protected]

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