OCEANSKIPPER is the only and first certificated/authorized company by the Administration as compass adjuster in the Philippines. Thru its

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 corrector. The deviations on principle headings, typically the cardinal (N, E, S & W) headings and inter-cardinal (NE, SE, SW & NW) headings are identified, and then corrector are employed to either completely remove or reduce the deviation. Corrector 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.

OPERATION, MAINTENANCE AND TESTING OF MAGNETIC COMPASSES

1.) Regulation 19, paragraphs 2.1.1, 2.1.2, 2.1.3 and 2.2.1 lay down the requirements for all ships (excluding fishing vessels and pleasure craft under 150 gt) to be fitted with a magnetic compass or other means to determine and display the vessel’s heading independent of any power supply. They must also be fitted with a pelorus, or other means, to take bearings over an arc of 360° of the horizon and a means for correcting heading and bearings to true at all times.

2.) Fishing vessels and pleasure craft under 150gt should comply with the requirements of the relevant MCA Code.

Performance standards

3.) Equipment must comply with the IMO Performance Standards as follows:
Magnetic compasses – Resolution A.382(X) and
Transmitting magnetic heading devices – Resolution MSC.86(70), annex 2

4.) Regulation 19 requires all ships of 150 GT and over, and all passenger ships to carry a spare magnetic compass (or equivalent.)

Responsibility for Maintenance

5.) The Owner and the Master are responsible for ensuring that compasses on their ships are maintained in good working order.

Adjustment of Compasses

6.) Each magnetic compass required to be carried by the Regulations shall be properly adjusted and its table or curve of residual deviations available at all times. Magnetic compasses should be adjusted when:

a.) they are first installed;

b.) they become unreliable;

c.) the ship undergoes structural repairs or alterations that could affect its permanent and induced magnetism;

d.) electrical or magnetic equipment close to the compass is added, removed or altered; or,

e.) a period of two years has elapsed since the last adjustment and a record of compass deviations has not been maintained, or the recorded deviations are excessive or when the compass shows physical defects.

Effects of Changes in Magnetism During the Life of a Ship

7.) Because the magnetism of a new ship can be particularly unstable, the performance of magnetic compasses should be monitored carefully during the early life of a ship, and adjustments made if necessary.

8.) Masters are advised that it is essential to check the performance of magnetic compasses particularly after:

a.) carrying cargoes which have magnetic properties;

b.) using electromagnetic lifting appliances to load or discharge;

c.) a casualty in which the ship has been subject to severe contact or electrical charges; or,

d.) the ship has been laid up or has been lying idle – even a short period of idleness can lead to serious deviations, especially for small vessels.

9.) Further to 8(b), the retentive magnetism can alter a ship’s magnetism, making compasses unreliable. However, a large amount of the magnetism induced by an electromagnet may subsequently decay so immediate readjustment is not advised. Every effort should be made to determine the compass deviation.

Monitoring Compass Performance

10.) Compass performance should be monitored by frequently recording deviations in the compass deviation book. Compass errors should be determined after every large alteration of course, and at least once every watch when there have been no major course alterations. Checking the compass deviation regularly may show the need for repair, testing or adjustment. In addition, compasses should be inspected occasionally by a competent officer or compass adjuster.