CMRT Cheat Sheet 2026

The 30 highest-yield CMRT facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Per SOLAS requirements, how often must a ship's radar be tested for proper operation? → Before each voyage and during each navigational watch as appropriate
2. What is the FIRST step a CMRT professional should take before operating any equipment? → Conduct a pre-operation inspection and verify safety systems
3. What is the PRIMARY purpose of obtaining CMRT certification in Certified Marine Radar Technician? → To demonstrate verified competency and adherence to professional standards
4. Which NMEA sentence is most commonly used to feed GPS position data into a marine radar system? → NMEA $GPGLL or $GPRMC
5. What does radar stand for? → Radio Detection and Ranging.
6. What is the role of the heading sensor interface in a marine radar system? → Provides vessel heading to stabilize the radar picture and enable true bearing readout
7. What does ARPA stand for in marine radar systems? → Automatic Radar Plotting Aid
8. Which IMO resolution sets the current performance standards for shipborne radar equipment? → MSC.192(79)
9. What is the role of radar reflectivity in detection? → It determines how easily the radar can detect the object.
10. What should be done if a radar system experiences signal loss? → Check antenna alignment and signal processing.
11. What is a 'blind sector' on a marine radar display? → An area of no radar coverage caused by an obstruction such as a mast or funnel
12. What is the function of a modulator in a marine radar transmitter? → It generates the high-voltage pulse that triggers the magnetron to emit a microwave burst
13. A CMRT technician installs a replacement radar on a U.S.-flagged SOLAS vessel. Which document must be updated to reflect the new installation? → Ship's Safety Radio Certificate
14. Which preventive maintenance approach is MOST effective for CMRT professionals managing equipment? → Schedule regular maintenance based on manufacturer recommendations and usage patterns
15. What is the purpose of regular maintenance for radar systems? → To ensure optimal performance and longevity.
16. What is the VRM (Variable Range Marker) used for in radar navigation? → Measuring the range to a specific target or point of interest on the radar display
17. What ARPA alarm is triggered when a tracked target's CPA and TCPA fall within user-set threshold values? → Collision alarm (CPA/TCPA alarm)
18. What is the function of the Electronic Bearing Line (EBL) on a radar display? → Measures the bearing to a target from own ship
19. How should radar cables be maintained? → By keeping cables free from damage and corrosion.
20. What ITU frequency band is used by S-band marine navigation radar? → 2.9–3.1 GHz
21. Under SOLAS Chapter V, which classes of vessels are required to carry an approved radar system? → Cargo ships of 300 GT or more and all passenger ships on international voyages
22. Which U.S. federal agency has primary authority over the radio-frequency spectrum used by marine radar systems in U.S. waters? → Federal Communications Commission (FCC)
23. How can a radar system's antenna be repaired? → By realigning, replacing components, or cleaning the surface.
24. What is the typical duty cycle of a marine radar transmitter? → 0.1 to 2 percent
25. What does a high noise figure in a radar receiver indicate? → Poor receiver sensitivity due to significant internally generated noise
26. What is the IMO-specified maximum range error tolerance for marine navigational radar? → ±1% of the range scale in use or 30 meters, whichever is greater
27. When conducting a risk assessment for CMRT operations, which factor should receive the HIGHEST priority? → Probability and severity of potential harm
28. What type of interference on a radar display typically appears as a series of dots or dashes in a spiral or rotating pattern? → Radar-to-radar interference from another vessel's radar operating on a similar frequency
29. Which preventive maintenance approach is MOST effective for CMRT professionals managing equipment? → Schedule regular maintenance based on manufacturer recommendations and usage patterns
30. Which foundational principle is MOST important for success in the Certified Marine Radar Technician profession? → Commitment to continuous learning, ethical practice, and quality outcomes