About Kahlenberg UK

Kahlenberg UK Ltd is the European distributor for Kahlenberg Industries, Inc. providing full European support and local stock for Kahlenberg marine and industrial air horns, sound signals, controllers, air compressors and the company's other products.

Please contact us for further assistance at or on +44 (0)1635 35353

Sound signal legal requirements

IMO COLREGs bookWhile countries across Europe will have local laws that apply to ship and boat navigation, there is a common requirement worldwide for all leisure, commercial and military vessels to conform to the IMO International Regulations for Preventing Collisions at Sea. As Steve Austin, Senior Policy Lead at the UK Maritime & Coastguard Agency (MCA) explains: "The COLREGs apply to all vessels, there is no differentiation between coded and non-coded vessels. Should the whistles prove not to conform then they will need to be modified or changed."

"Whistles should conform to the performance in COLREGs, Appendix III and the appropriate parts of IEC 60945 to EN60945 which deal with the marine operating environment."

All Kahlenberg products meet or exceed these requirements. Many other new and currently installed sound signals are non-compliant and might be breaching maritime law and invalidating insurance cover.

M-522C Sound Signal Controller

Kahlenberg M-522C marine sound signal controllerThe new Kahlenberg M-522C Sound Signal and Light Controller provides automated sound and light signals according to IMO and SOLAS requirements in a user friendly format. The M-522C controls multiple horns or whistles and a morse light' it can also be configured to work with external alarm systems and sound surveillance systems.

The M-511C not only automatically sounds the appropriate signal for restricted visibility requirements under Rule 35 of the International Regulations for Preventing Collisions at Sea, 1972 (COLREGs), but also performs manoeuvring codes, a danger code and general alarm as well as offering a standard 'at-will' button. It completely frees the skipper, master or watch from remembering the frequency of sound signals, leaving them able to fully focus on the safety of their boat or ship.

The features of the M-522C include:

  • Rugged construction to marine standards
  • Generates IMO ColReg Rule 35 restricted visibility signals
  • Generates IMO ColReg Rule 34 manoeuvring code signals
  • Produces SOLAS General Emergency Alarm and Abandon Ship Codes via external push buttons
  • Features on command and automatic control of all connected horns and lights
  • Multiple M-522C controllers can be linked together
  • Illuminated and dimmable display
  • Watertight to IP65
  • Switching capacity 2A each AC or DC
  • Mute connection for external sound surveillance systems
  • Connects to any external push buttons

The Kahlenberg M-522C Sound Signal Controller is available in 8V-30V DC and 100-240V 50Hz-60HzAC versions. It can be flush-mounted or bulkhead-mounted

Kahlenberg M-522C Sound Signal Controller downloads

Kahlenberg M-522C Sound Signal Controller technical information (PDF 133Kb)

Further information

Call Kahlenberg UK now on +44 (0)1635 35353 or email