What is the purpose of the lubber line on a compass?

The lubber line on a compass serves the vital function of indicating your travel direction. This line is usually marked on the compass housing and aligns with the direction in which the compass is pointed. When you orient the compass so that the magnetic needle points to magnetic north, the lubber line helps you determine the precise heading you are facing. This is essential for navigation, as it allows divers and other outdoor enthusiasts to chart their course accurately. By knowing your travel direction, you can effectively navigate underwater environments or other challenging conditions.