What is the purpose of hydrographic charts?

The purpose of hydrographic charts is primarily to provide information on underwater topography, which includes details about the seafloor's features such as depths, submerged objects, and types of seabed materials. These charts are critical for navigation, as they help mariners understand the underwater landscape and avoid hazards, ensuring safer travel across bodies of water.

Understanding the topography is essential not only for safe navigation but also for various marine activities including fishing, underwater construction, and environmental studies. Hydrographic charts often include depth contours, soundings, and other related data that are vital for efficient maritime operations.

In contrast, while charts can indirectly aid in marking shipping lanes, outlining coastal regulations, or air traffic routes, these are not their primary functions. Hydrographic charts are specifically designed to focus on the underwater features crucial for marine navigation and operational planning.