🔍 Key Concepts

• Zone time vs Greenwich Mean Time (GMT) / Universal Time Coordinated (UTC) in maritime communications • Standard single-letter time zone designators used in naval and aeronautical practice • How local time, zone description, and a leading letter are used together in messages/logs

💭 Think About

• Think about which single letter is commonly associated with universal standard time used on charts and in Notices to Mariners. • Recall how time is written in formal messages (e.g., 081500Z APR 25). Which part of that example indicates the time zone? • Which of the letters in the options is widely recognized internationally for a specific time standard, not just a local time zone?

✅ Before You Answer

• Verify which letter is used in examples of operations orders, weather reports, or NAVTEX messages to label the time. • Check a chart or a Notice to Mariners example to see how times are formatted with a trailing or leading letter. • Confirm which option represents the standard world reference time used for navigation and communications.