Which of the following is a principal component of a hydrographic survey?

The principal component of a hydrographic survey is seafloor composition. This aspect is crucial as it provides detailed information about the nature of the bottom surface in the area being surveyed. Understanding the seafloor composition is essential for multiple applications, such as determining suitable locations for construction, anchoring, and assessing habitats in aquatic environments. It also plays a significant role in nautical charting, aiding in navigation by indicating the types of sediments, rock formations, or other materials present on the seabed.

In contrast, while water temperature, atmospheric pressure, and wave height are important environmental parameters that can influence hydrographic conditions, they do not directly define the characteristics of the seafloor itself, which is the primary focus of a hydrographic survey. Water temperature can affect density and currents, atmospheric pressure can influence tidal readings, and wave height may impact survey techniques and safety, but understanding the seafloor composition is fundamental for accurately characterizing the underwater terrain.