Who Is Authorised to Adjust a Ship's Magnetic Compass — And Can Your Own Officer Do It?

In an earlier post we covered when a ship is legally required to adjust its magnetic compass under SOLAS Chapter V. That raises the obvious next question, and it is one operators get wrong surprisingly often: who is actually allowed to do the adjustment? Can the master simply swing the ship and re-card the compass, or does the law demand a specialist? And if your own officer holds a compass adjuster qualification, does that make them authorised to do it?

The answer is more layered than a yes or no, because SOLAS sets the obligation but leaves the question of who largely to flag states — and flag states do not all answer it the same way. Here is how it actually works, and where the practical opportunity lies for fleets.

SOLAS sets the standard but not the person

SOLAS Chapter V, Regulation 19 requires a properly adjusted standard magnetic compass and a current deviation table. What the convention text does not do is name who may carry out the adjustment. That detail is left to flag-state administrations and to the supporting international guidance — IMO Resolution A.382(X) and the testing-and-certification standard ISO 25862:2019.

What those sources, and flag-state marine notices built on them, consistently say is this: adjustment must be carried out by a duly authorised, qualified compass adjuster — or, where a qualified adjuster is genuinely unavailable and the master considers it necessary, by the master of the vessel, provided the master has the necessary expertise as a compass adjuster.

So there are two lawful routes, but they are not equal. The qualified adjuster is the norm; the master is the conditional fallback. Reading that fallback as a blanket permission for any master to adjust the compass whenever convenient is exactly the misreading that produces a deficiency at the next inspection.

Route one: the qualified compass adjuster

This is the default the rules assume. A compass adjuster is a skilled technician who measures the ship's magnetism, positions the correctors (fore-and-aft and athwartship magnets, soft-iron spheres, the Flinders bar and heeling magnet), swings the ship through known headings, and then issues a certificate of compass adjustment with a residual deviation table. Flag guidance typically requires that certificate to record the vessel's name, IMO number, call sign, flag, the place the work was done, and the adjuster's name, stamp and signature. ISO 25862:2019 sets the quality bar the work must meet — for a newly commissioned vessel, deviation on any heading should be no more than 3°, and no more than 5° thereafter.

One rule worth flagging because it trips people up: in most flag regimes, the same person who surveyed a vessel may not also adjust its compass. It is a deliberate separation to avoid a conflict of interest, so an attending surveyor cannot simply "also do the compass."

Route two: the master — but only under conditions

Yes, a master can lawfully adjust the compass — but the permission is hedged. It applies when a qualified adjuster is genuinely unavailable, the master judges adjustment necessary for safety, and the master actually has the expertise to do it competently. Australia's Marine Order 27, for instance, expressly allows a vessel's compass to be adjusted by the master, alongside a qualified compass adjuster, while still requiring that the work be done properly to the 5° standard.

The trap in that fallback is the word expertise. Adjustment is genuinely technical, and getting it wrong is not a harmless error — reducing deviation at one location can worsen it elsewhere as the ship changes magnetic latitude, so a botched adjustment can leave a vessel with a less trustworthy compass than before. A master without real training in the task is not the safety net the regulation imagines. Which leads directly to the most useful insight for fleet operators.

The elegant fix: make your own senior officer the qualified adjuster

Notice what happens if a master or senior navigating officer is themselves a properly trained, qualified compass adjuster. The "qualified adjuster unavailable" problem disappears — the qualified adjuster is on board, on every voyage. The vessel can be swung and re-carded when the rules require it, without waiting in port for an external technician or paying a call-out fee at every trigger event.

This is precisely why a growing number of operators train their own people rather than relying solely on external adjusters. The Magnetic Compass Adjuster course at Elite Offshore Academy — ABS Class-approved and TUV NORD ISO 21001-certified — is built to give a serving officer the genuine competence the role demands: the theory of ship magnetism, hands-on adjustment practice, and the ability to produce a compliant deviation table that will stand up to flag-state and Port State Control scrutiny.

The honest caveat: "qualified" and "authorised" are defined by the flag state

Here is the part it would be easy to oversell, so let me be straight about it. Completing a recognised, accredited compass adjuster course gives an officer the competence and a recognised qualification. Whether that qualification makes them authorised to adjust the compass on a specific vessel ultimately depends on that vessel's flag state and its recognition rules — and those rules vary:

• Some administrations define a "qualified compass adjuster" precisely as a person who has completed an approved training course. Australia's Marine Order 27 takes this approach — recognised training is the qualification.

• Some operate a formal national recognition or approval list. Germany, for example, recognises a small number of compass adjusters approved by its federal maritime authority.

• Some will accept adjusters recognised by another SOLAS-member state, provided the person has completed a compass adjustment course at a certified centre meeting the international standards — Panama's administration takes this kind of approach.

• Some, such as the United States, have no government licence at all, and the work is done by qualified private technicians whose competence is the operative requirement.

The practical rule for any fleet: treat a recognised qualification as the essential foundation — you cannot be authorised anywhere without genuine competence — and then confirm the specific flag state's recognition requirement for the vessels you operate. A credible training provider will be clear about what its certificate is and is not, rather than promising blanket worldwide authorisation that no single certificate can deliver.

So, can your own officer do it? A clear summary.

• A qualified compass adjuster — the default, expected route under SOLAS and flag rules.

• The master — lawful as a fallback, only when a qualified adjuster is unavailable and the master genuinely has the expertise.

• Your own officer, trained and qualified — the best of both: an on-board, competent adjuster who removes the "unavailable" problem entirely. Confirm their qualification is recognised by your vessels' flag state.

• Not permitted: an untrained crew member improvising, or the same person who surveyed the vessel also adjusting its compass.

The bottom line

SOLAS demands a properly adjusted compass but leaves the question of who to flag states, which expect a qualified compass adjuster and allow the master only as a conditional fallback. The smartest position for an operator is to stop depending on whoever happens to be available and instead build the competence into the crew — turning a recurring scramble for an external adjuster into a capability you own. Just remember that genuine, recognised qualification is the foundation, and flag-state recognition is the final check.

If equipping one of your own officers with that qualification is the direction you are considering, the Magnetic Compass Adjuster course page sets out exactly what the training covers and who it is for. (In an upcoming post we will put real numbers to the in-house-versus-external choice — the lifetime cost case for training your own adjuster.)

Frequently asked questions

Can a ship's master legally adjust the magnetic compass?

Yes, but only as a conditional fallback: when a qualified compass adjuster is genuinely unavailable, the master considers adjustment necessary, and the master actually has the expertise to do it competently. The default expectation under SOLAS and flag-state rules is a qualified compass adjuster.

Who counts as a "qualified" or "authorised" compass adjuster?

It is defined by the flag-state administration and varies. Some flags define it as someone who has completed an approved training course; some maintain a national recognition list; some accept adjusters recognised by other SOLAS states; and some, like the US, have no government licence and rely on competent private technicians. A recognised qualification is the common foundation everywhere.

Does a compass adjuster certificate authorise someone to work on any ship worldwide?

Not automatically. A recognised certificate proves competence and qualification, but authorisation to adjust a specific vessel's compass depends on that vessel's flag-state recognition rules. Always confirm the flag's requirement.

Can the surveyor who inspects the vessel also adjust the compass?

No. Most flag regimes prohibit the same person who surveyed a vessel from also carrying out its compass adjustment, to avoid a conflict of interest.

Why train our own officer instead of hiring an external adjuster?

A trained, qualified officer on board removes the "qualified adjuster unavailable" problem, lets the vessel be adjusted promptly when the rules require it, and avoids repeated external call-out costs — provided the officer's qualification is recognised by your vessels' flag state.