Air horn (for ships > 20 m and < 75 m)
1M Cunningham Air Whistles

• 

  Air horn (for boats < 20 m)
  1L
  
• 

  Air horn (for boats < 20 m)
  2L
  

Acoustic signalling for ships

• 

  Air horn (for ships > 20 m and < 75 m)
  3M
  
• 

  Air horn (for ships > 20 m and < 75 m)
  2M
  
• 

  Air horn (for ships > 20 m and < 75 m)
  4H
  
• 

  Air horn (for ships > 20 m and < 75 m)
  2H
  
• 

  Air horn (for ships > 20 m and < 75 m)
  4L
  
• 

  Air horn (for ships > 75 m and < 200 m)
  5H
  
• 

  Air horn (for ships > 20 m and < 75 m)
  3H
  
• 

  Air horn (for ships > 20 m and < 75 m)
  5L