Hydrographic surveying — hydrographic surveys primarily deal with the mapping and charting of which domain?

Introduction / Context:
Hydrographic surveys provide depth, seabed characteristics, shoreline features, and hazards necessary for navigation, coastal engineering, dredging, and resource management. Unlike terrestrial topographic surveys, they are conducted over water and require specialized methods and instruments to determine underwater topography (bathymetry).

Given Data / Assumptions:

• Focus is on oceans, seas, lakes, reservoirs, estuaries, and navigable rivers.
• Survey outcomes include bathymetric charts, nautical charts, and coastal maps.
• Measurements include depths (soundings), tides, currents, and seabed sediment types.

Concept / Approach:

Hydrography is the science of surveying and charting large water bodies. It uses echo sounders, sonar, GPS/RTK positioning, tide gauges, and current meters to produce accurate bathymetric datasets. Terrestrial tools (levels, total stations) are used only for coastal tie-ins. Products support safe navigation and engineering works such as breakwaters, ports, and dredging projects.

Step-by-Step Solution:

Verification / Alternative check:

International standards (e.g., IHO S-44) define hydrographic survey requirements for nautical charting—explicitly focused on water bodies.

Why Other Options Are Wrong:

Heavenly bodies — astronomy, not surveying.
Mountainous region — terrestrial topography.
Canal system — a subset of water infrastructure; hydrography broadly covers larger natural water bodies.
Movement of clouds — meteorology.

Common Pitfalls:

Confusing hydrography with hydrology (scientific study of water in the environment); hydrography is about mapping and charting.

Final Answer:

large water bodies