Auto-Distress Alarms are characterized by which of the following?

• A. Alternating 1300 Hz and 2200 Hz tones for 30-60 seconds
• B. A single fixed tone at 1500 Hz for 15 seconds
• C. A siren that remains constant at 2000 Hz for 60 seconds
• D. An alarm that only pulses visually

Answer: (A)

Auto-distress alarms use a distinctive audible pattern to signal an emergency and prompt immediate action. The standard signature is alternating tones at 1300 Hz and 2200 Hz, cycling for about 30 to 60 seconds. This back-and-forth tone is designed to cut through typical shipboard or sea noise and be unmistakable as a distress signal, quickly notifying crew and nearby responders and triggering the appropriate distress procedures. The other patterns— a single fixed tone, a continuous constant siren, or a visual-only alert—don’t deliver the same immediate grab or be reliably audible in noisy conditions, so they aren’t used to denote Auto-Distress Alarm.