Which component of the compass compensates for magnetic deviation?

The component of the compass that compensates for magnetic deviation is the adjustable weights. Magnetic deviation occurs when the magnetic fields from the vessel itself interfere with the magnetic compass, causing it to indicate an incorrect heading. To correct for this deviation, adjustable weights (also known as deviation correction weights or compensating weights) can be positioned on the compass to balance out these magnetic influences.

These weights are strategically placed to alter the magnetic field around the compass, ensuring that the compass reading aligns as closely as possible with true magnetic north, thereby improving navigational accuracy.

The other components mentioned, such as gimbals, the card, and the lubber's line, play important roles in how the compass operates—ensuring stability, displaying readings, and indicating the direction of heading, respectively—but they do not directly address the issue of magnetic deviation. Gimbals allow the compass to remain level in a moving vessel; the card is the rotating disc that displays the direction; and the lubber's line is the fixed reference line that shows the direction of travel.