How many degrees is a magnetic compass card marked in?

A magnetic compass card is marked in 360 degrees. This full circle representation allows navigators to determine their heading in relation to true north or magnetic north. Each degree corresponds to one part of the 360 degrees in a complete circle, which provides precise navigation information.

The use of a 360-degree system is standard in navigation and allows for detailed and accurate directional readings, which are essential for safe and effective maritime navigation. The compass card typically includes markings every 10 degrees, with additional subdivisions, to help users read directions more easily. This level of detail is critical in avoiding navigational hazards and ensuring accurate course plotting at sea.

The other options, such as 90 degrees or 180 degrees, represent parts of a circle rather than a full representation. A 400-degree system is not standard in a traditional compass, making 360 degrees the correct and universally accepted measurement for magnetic compass cards.