What mode may be used to adjust or swing your compass?

The mode used to adjust or swing your compass is the magnetic mode. The compass works based on the Earth's magnetic field, and as such, it is subject to variations and deviations caused by nearby metallic objects, electronic devices, and the vessel's own magnetic field.

When you conduct a compass swing, you are aligning the compass with the true magnetic north to determine and correct for any deviation, which is important for accurate navigation. This process allows you to ensure that the readings you obtain from the compass are as accurate as possible, considering the magnetic influences that might distort its performance. Understanding the magnetic mode and how it interacts with the compass is essential for navigational accuracy while at sea.

Other modes, such as true, gyro, and relative, refer to different methods of navigation or course determination and do not specifically pertain to the adjustment of the magnetic compass.