Describe the methodology for conducting a hydrographic survey for port development.

Hydrographic survey methodology: establish tidal datum through long-term gauge observations. Control survey connects project to national datum. Bathymetry using multibeam echosounder (full coverage) or single beam on planned lines. RTK-GPS provides position, motion sensor corrects for heave/pitch/roll. Sound velocity profiling for depth accuracy. Survey coverage at 100% for navigation channels. Data processing: tide reduction to chart datum, noise filtering, surface generation. Products: bathymetric charts, cross-sections, dredge volumes. Side-scan sonar identifies seabed features and obstructions. Sub-bottom profiler for geological investigation. Compliance with IHO S-44 standards for hydrographic surveys.