Compass Adjustment is the method of analyzing and compensating for deviating forces of a vessel’s magnetic compass. A magnetic compass should always align steadily to the earth’s magnetic field, pointing to magnetic north.

However, steel, electronic instruments or equipment, and even the type of cargo carried, can cause the compass needle to point away, or deviate, from magnetic north. Compass adjustment is necessary to compensate these deviating forces with correctors. The deviations on principle headings, typically the cardinal (N, E, S & W) headings and intercardinal (NE, SE, SW & NW) headings are identified, and then correctors are employed to either completely remove or reduce the deviation. Correctors may be permanent magnets or soft iron, which are placed adjacent to the compass. This creates equal, but opposing magnetic fields, thus nullifying the deviating fields around the compass, enabling it to align correctly. Now, the earth’s magnetic field can pass through the compass without being deflected out of its normal path. For various factors such as design, location and the vessel’s unique magnetic properties, all the deviation may not be removed. The residual deviation is recorded on a deviation card as a table or a curve of deviation against the compass headings.

Although there may be many technically advanced components on board, the magnetic compass still remains a vital component of all in guiding the crew across the seas. The magnetic compass is a proven piece of instrument which can work independently apart from all the other components.

Compass readings must be precise and accurate to the point as the crew depends on it. A nullified magnetic compass is the one which guides the ship in the right direction.

Our qualified engineers are certified instrumentalists who can fine tune the compass and nullify any external magnetic forces on the device. Tuning the compass is also called “Swinging the ship”

Comparing readings from the compass with that of the actual known bearings will have the device tuned to precision.

Ships magnetic compass needs to be adjusted under the following conditions

• 1. When first installed on board
• 2. When the ship has been dry docked
• 3. When major structural work is carried out
• 4. If any other electric or magnetic devices are installed or removed near the device
• 5. Once in every two years

Service and Certification
After every successful tuning of the magnetic compass, it needs to be certified. Our engineers are trained professional in tuning your magnetic compass to precision and also can certify the instrument for its working. The intricacies and the components inside a magnetic compass are not to be messed with by an untrained professional. Only qualified and certified engineers can tune the compass as the liquid inside the compass needs to be fixed precisely and not to be mixed with one another. We at Chennai Marine Services can Install, tune and certify the condition of your magnetic compass both on board or offshore.