This control shall be used when shipboard radar is inoperative or degraded as to be inadequate to provide radar separation under conditions normally requiring positive control.

• A. Non-radar
• B. Advisory control
• C. Positive control
• D. Monitor

Answer: (A)

When radar is unavailable or degraded to the point where it can’t provide radar separation, you switch to non-radar (procedural) control. This approach relies on time and distance standards, pilot position reports, published routes, and clear communications rather than radar surveillance to maintain safe separation. The idea is to keep aircraft separated through procedure and coordination, not through radar vectors.

That’s why this is the best choice: it specifically addresses maintaining separation without radar, using procedural methods. Advisory control would not guarantee separation since it’s mainly guidance without assured separation; positive control depends on radar to ensure spacing; monitoring involves watching traffic without actively providing separation. Non-radar provides the structured method used when radar can’t provide the necessary separation.