MAGNETIC COMPASS
A Magnetic Compass is a mandatory marine navigation instrument that indicates a vessel’s heading relative to magnetic north using the Earth’s magnetic field. As per SOLAS Chapter V (Regulation 19) and IMO requirements, every seagoing vessel must be fitted with a properly adjusted magnetic compass independent of electrical power.
Is a magnetic compass mandatory under SOLAS?
Yes. SOLAS Chapter V, Regulation 19 requires all ships to carry a standard magnetic compass, regardless of ship size or equipment fit.
Why is a magnetic compass required when gyro compass is installed?
IMO mandates a magnetic compass as an independent backup in case of gyro or electrical failure.
Does a magnetic compass require power?
No. A magnetic compass operates without electrical power, making it reliable during blackouts.
What is meant by “properly adjusted” magnetic compass?
It means the compass has been corrected for deviation and verified by a qualified compass adjuster.
How often must a magnetic compass be adjusted?
Adjustment is required:
After major structural changes
After installation of new equipment
When deviation becomes excessive
As per flag state or surveyor recommendation
What documents are required for a magnetic compass?
A Deviation Card must be displayed near the compass, as required by IMO guidelines.
Where should the magnetic compass be installed?
It must be installed in a location with minimum magnetic interference and provide a clear view for taking bearings
Is a compass bearing device required?
Yes. SOLAS requires a bearing device (such as an azimuth mirror or pelorus) to take visual bearings.
How is compass accuracy verified during inspections?
Port State Control (PSC) and Class surveyors check:
Compass condition
Deviation card validity
Proper illumination
Correct heading comparison
Can a magnetic compass be replaced by electronic systems?
No. Electronic or GPS-based compasses cannot replace the magnetic compass under SOLAS requirements.
Conclusion
The magnetic compass remains a mandatory and indispensable navigation instrument under SOLAS and IMO regulations. Its ability to operate independently of power and electronic systems makes it a critical backup for safe navigation. Proper installation, regular adjustment, and valid documentation ensure compliance with international regulations and support reliable vessel operation during normal and emergency conditions.