Magnetic, gyro and heading systems
What is being checked
The inspector is checking whether magnetic and gyro compasses and distributed heading outputs remain accurate, deviations are monitored and officers recognise disagreement before navigation systems are corrupted, with officers able to configure, cross-check, test and respond to failure of the actual equipment fitted.
Ready onboard
0/6 completePractice questions
Answer aloud, then open the preparation point.
1What safety function does magnetic, gyro and heading systems provide?
Magnetic and gyro compasses and distributed heading outputs remain accurate, deviations are monitored and officers recognise disagreement before navigation systems are corrupted.
2How is the complete function tested?
Compare master gyro and repeaters, determine compass error by reliable azimuth or transit, inspect the magnetic compass, test alarms and verify heading outputs to radar, ECDIS, AIS and VDR.
3What is its principal limitation?
Gyro error can change with speed, latitude, power interruption or equipment fault; magnetic deviation changes with ship magnetism and nearby equipment.
4What is your response if it fails?
Select an independent approved heading source, apply measured error, change to manual steering if required, notify the Master and assess all dependent systems.
5Show the latest test and operational evidence.
Link the dated record to the actual unit, test method, result, defect response and restoration; a panel lamp test alone is not sufficient where the full signal path can be tested.
Where an observation may arise
The responsible officer cannot explain safe use, limitations or failure response.
Testing does not prove the required operational function or remote indication.
Opportunities exist but compass errors are not determined or recorded.
A repeater or dependent system shows unrecognised heading error.
Officers cannot identify which heading source feeds critical equipment.
Master's practical note
Follow one heading source through radar, ECDIS, AIS and steering. A single gyro fault can create several agreeing but equally wrong displays.
Equipment boundary and references
Equipment boundary: Required compass fit and permissible errors depend on SOLAS, flag and installation approval. GNSS heading is not a substitute for the required magnetic compass and may share satellite vulnerabilities.
References
- OCIMF SIRE 2.0 Question Library Part 1, Version 1.0, Question 4.1.12
- SOLAS Chapter V regulations 19 and 27
- IMO Resolution A.382(X)
- ICS Bridge Procedures Guide
Last reviewed: 2026-09-11