What must be included in hydrographic surveys for navigational aids?

In hydrographic surveys, particularly for the purpose of establishing navigational aids, it is crucial to include information that supports the safe navigation of vessels. This includes sufficient topography for landmarks, which is vital to help mariners recognize their position and navigate effectively. Topographical features provide reference points that can be used in conjunction with charts and instruments, enhancing situational awareness.

Including submerged or land-based topography assists in the identification of navigational routes and assists mariners in avoiding hazards. Sufficient topography can also highlight changes in the shoreline or underwater structures, which are essential for safe passage and for understanding the navigational characteristics of a waterway.

Other aspects like depths and currents, hazards to navigation, and the weights of watercraft are certainly important considerations in nautical surveys. However, these elements alone would not replace the need for topographical information, which directly influences navigation and wayfinding. Therefore, incorporating sufficient topography for landmarks is a critical requirement for ensuring safe navigation as part of hydrographic surveys.