Ensuring the proper maintenance and testing of magnetic compasses onboard is vital for safe maritime operations. According to Chapter V, Regulation 19 of the 2000 amendments to the 1974 SOLAS (International Convention for the Safety of Life at Sea), the use of magnetic compasses is mandatory for all vessels. To meet these standards, ship owners, operators, and captains are responsible for maintaining their magnetic compasses in optimal working condition.

The Panama Ship Registry has recently updated its Merchant Marine Circular, offering clear guidelines for compass maintenance and testing. These regulations apply to vessels of all sizes, across different navigation areas.

Essential Maintenance Guidelines for Magnetic Compasses

Magnetic compasses require adjustment in several circumstances:

• • When they are first installed or replaced

• • If they become unreliable or show physical defects

• • When the ship undergoes structural changes affecting its magnetic fields

• • If electromagnetic equipment is installed near the compass

• • After one year has passed without proper deviation records or when deviations exceed the allowable limits

• • When deviation exceeds 5 degrees, factoring in the geographical variation and methods used

Performance Monitoring and Necessary Adjustments

During the early stages of a ship’s life, its magnetism can be particularly unstable, and the compass should be carefully monitored for any irregularities. Regular checks are necessary when:

• • Carrying cargoes with magnetic properties

• • Using electromagnetic lifting appliances

• • After incidents involving electrical malfunctions or contact

• • When a vessel has been idle for a period, as even short periods of inactivity can cause significant deviations, especially in smaller vessels.

It’s important to understand that the retentive magnetic field of a ship can distort compass accuracy. However, the induced magnetism from nearby electromagnetic equipment can fade over time. This means immediate readjustments are unnecessary unless the deviation shows significant errors. Regular monitoring and the recording of deviations in a compass deviation log can indicate if repairs or adjustments are needed.

Adjustment and Repair Procedures

Compass adjustments must be performed by an authorized compass adjuster. In the absence of a certified adjuster, the master of the vessel may make adjustments, provided they have sufficient expertise. Panama’s regulations also recognize compass adjusters certified by SOLAS member states, and these professionals must have completed a certified compass adjustment course. Adjustments should never be made by the same person who surveyed the vessel.

Key considerations during compass maintenance include:

Once adjustments are complete, the vessel should receive a certificate detailing the date, adjuster’s name, compass specifications, method of adjustment, and the results.

Compass Repairs

Compass repairs should only be handled by the manufacturer or an authorized repair company with the appropriate facilities. Upon completing repairs, the technician must provide a certificate confirming that the work meets international standards.

For onboard equipment, it is essential to avoid placing portable electrical devices (e.g., radios and steel objects) near the compass, as these can disrupt its functioning.

Spare Compass Bowl

If a spare magnetic compass bowl is required, it should be stored carefully in a location away from the bridge structure to ensure it remains unaffected by any potential damage to the bridge.

Transmitting Magnetic Compasses (TMC)

When a standard magnetic compass is modified to provide a transmission output, it must undergo recertification with the transmitting element in place. Modifications should only be carried out by experienced compass technicians to ensure compatibility with the binnacle. The compass cannot be relied upon for navigation until it has been properly recertified and adjusted.

For auxiliary equipment added to the compass system, such as electronic units or power supplies, type testing is required to ensure that they do not interfere with compass performance, particularly in avoiding the impact of radio frequency transmissions.

If a transmitting compass is used for heading information, a transmitting element should be added to the spare bowl, with separate testing required for this setup. Alternatively, if the compass is used for repeater functions, the spare bowl does not require an additional transmitting element.

By adhering to these maintenance and adjustment guidelines, vessel operators can ensure that their magnetic compasses remain reliable for safe navigation at sea.