Plastimo tips & tricks
Does my compass need to be compensated ?
Magnetic fields generating interference on the compass performance exist on all boats. The impact on the compass, called "deviation", can originate from many different sources : metallic masses, loudspeakers, engine, electronic instruments…
If deviation ranks between 7 and 20°, your compass should indeed be compensated.
Our compasses are supplied with built-in compensation, or can be further equipped with an optional compensation cell. They are designed to be user compensated.
Compensating a compass consists in adjusting the position of the 2 magnets, in order to affect the horizontal component of the card by modifying the North/South and East/West deviation.
How to compensate a compass
Use a second compass as the reference ; a handbearing compass is often the most convenient, provided it is interference-free. The North-South screw corrects North-South heading ; the East/West screw corrects East-West heading.
• Run the boat along the Northerly course selected as per your handbearing compass and adjust your steering compass by turning the North and South screws either way, so that the steering compass also points North.
• Repeat the procedure, running the boat Easterly.
• Run the boat Southerly and this time, reduce the deviation by half.
• Run the boat Westerly and reduce the deviation by half.
• Note : Upon completing the compensation procedure, it is essential to draw a new deviation table.