These are some of the most frequently asked questions by our clients. If you do not find a solution to your query, please do not hesitate to contact us.

The magnetic field of a container always changes by small amounts. Some may cause the deviation to change from the current deviation table. This can create problems in navigation when using the magnetic compass, as the enlarged deviation causes the magnetic compass to behave erratically and also causes the compass card to move excessively when the vessel is rolling.

The cause of the increase and changes in deflection can have different origins. There are a multitude of influences that can make a magnetic compass unreliable. Not only the load can influence the ship’s deflection, but also changes in the ship’s steel, lightning and the installation of nearby electronic devices can have an effect.

Depending on the port and the port stay of the vessel, the compass adjuster will usually carry out a pre-inspection to check the magnetic compass, the table of the last deviations, the compass logbook and to verify if all necessary data and (spare) correctors are available. If during this pre-inspection the compass fitter finds something wrong, our fully certified compass service department can check, repair or replace your damaged compass or binnacle in time for the vessel to depart without delay. This pre-inspection depends on your schedule and availability.

If any of the correctors are missing or damaged, we have the most common types in stock for quick delivery. We also have spare magnets from all types of magnetic compass manufacturers in stock, so there is no need to cancel the compass setting due to unavailability of the correct magnets.

If everything is in good working order, the compass adjuster will keep in close contact with the ship’s port agent and board the ship prior to departure, where he will sail the ship out to sea. There, the compass adjuster will perform compass adjustment during a compass swing and eliminate/reduce near-zero deviation. The remaining deviation shall be recorded in the deviation table and handed over to the master prior to disembarkation. Depending on the size of the ship, the compass adjustment may also be completed within port limits to minimise costs.

Generally, the actual compass setting is 1 hour and 30 minutes of ship’s roll. After the compass adjustment, the compass adjuster leaves together with the pilot.

The main reason for the adjustment of the compass and the publication of a new deviation table is an increase in deviations. However, port inspections, state control, verification inspectors and flag state audits may also trigger the need to adjust the compass.

The only way to check that a magnetic compass is working properly before adjusting the magnetic compass is to use a small screwdriver to offset the magnetic compass heading by 2 degrees.

Once the screwdriver has been removed, the magnet should return to its initial course within 5 to 10 seconds.

One of the most common causes of deviation is caused by an incorrect amount of Flinders bar during a previous adjustment of the compass. This is indicated by an increasing or decreasing deviation when a ship sails on an easterly (SE-NE) and/or westerly (SW-NW) course over a large difference in latitudes.

A certified compass adjuster can eliminate these deviations.

Because the compass adjuster needs the compass logbook data to decrease these changes in deviation, it is of utmost importance that all compass logbook data is true and accurate to ensure that the compass adjustment is successful.

Also the last deviation table that was given to the master during the last compass adjustment should be available.

Depending on the length of the vessel, the magnetic field in a newly constructed vessel may take some time to settle. For vessels of 100 metres in length 5 to 6 months and normally 8 to 9 months for vessels over 180 metres.

Due to the influence of the ship’s magnetic field on the magnetic compass, it may be the case that on some courses the deviation is overcompensated and then it is not necessary to remove 1 or even both Globes (D-Correctors) during compass adjustment.

Lifeboats have their own magnetic field, which is generally too small to affect their magnetic compass.

However, because this lifeboat is on board the ship, the magnetic field of the ship has great influences on the magnetic compass of the lifeboat, as this compass has not been adjusted for this additional influence.

After all, if the lifeboat is used, it will no longer be influenced by the ship’s magnetic field and the magnetic compass will show the correct course.