🔍 Key Concepts

• SART (Search and Rescue Transponder) behavior on an X-band radar display • How a SART echo changes as the rescue vessel gets closer • Difference between DSC (Digital Selective Calling) alerts and radar-based indications

💭 Think About

• Focus on which bridge instrument actually "sees" a SART: is it the VHF/DSC set or the X-band radar? • Think about what happens to the pattern of returns from a SART on the radar screen as the range closes from several miles to very close • Ask yourself which option describes a progressive visual change on the radar that clearly indicates you are very near the SART

✅ Before You Answer

• Verify which frequency band a standard SART operates on (9 GHz X-band radar). • Check which of the answers mentions a distinctive change in the radar picture as you get very close. • Confirm that DSC alarms are not the primary means for detecting a SART in the immediate vicinity.