🔍 Key Concepts

• GMDSS (Global Maritime Distress and Safety System) voice distress frequency on 2182 kHz • Historic requirement for using silent periods so weak distress calls can be heard • Relationship between silent periods and the top of the hour

💭 Think About

• Think about why silent periods were established on distress frequencies. When would they be most predictable and easy for all ships to observe at the same time? • Look at the pattern of the answer choices: they are paired times in the hour. Which pair best matches the traditional international radio watchkeeping schedule? • Consider how often per hour a 3‑minute silent period should occur to balance regular traffic and the need to hear distress calls.

✅ Before You Answer

• Verify which two specific minutes past the hour are traditionally reserved as international radio watchkeeping silent periods on 2182 kHz. • Check that the total silent time per hour is 6 minutes (2 silent periods × 3 minutes each). • Confirm that the correct option shows times evenly spaced within the hour.