Nautical bells and whistles are mandatory acoustic devices for signaling at sea, according to maritime regulations. They serve to improve safety and communication between vessels, especially in conditions of poor visibility.

Types of Nautical Acoustic Devices

🔹 Nautical whistles – Mandatory for vessels up to 12 meters. They must produce a clear sound that can be heard from a distance.

🔹 Nautical bells – Mandatory for vessels over 12 meters. They must have a minimum diameter of 300 mm and produce a deep, distinctive sound.

🔹 Fog horns and sirens – Mandatory on vessels over 20 meters, they provide a more powerful sound for navigation in fog or low visibility conditions.

Regulations and Obligations

✔ Up to 12 meters → Whistle required
✔ Between 12 and 20 meters → Whistle and bell required
✔ Over 20 meters → Whistle, bell and fog horn required
✔ Navigation in fog → Acoustic signals at regulated intervals (ColReg 72)

Materials and Power Supply

✅ Brass and Bronze – Corrosion-resistant materials, ideal for nautical bells.
✅ Plastic and Stainless Steel – Used in whistles and fog horns for durability.
✅ Manual or Electric – Whistles can be mouth-operated, air-pressured, or electronic.

Regularly check the condition and operation of your sound system to ensure compliance with regulations.