Tidal Patterns and Their Influence on Navigation in the Calabar Port Channel

Tidal dynamics exert critical influence on navigational safety and port operational efficiency, particularly in estuarine port environments characterised by shallow draught constraints. This study examines tidal patterns in the Calabar Port channel, Cross River State, South South Nigeria, and evaluates their implications for vessel navigation, cargo scheduling, and port accessibility. Tidal gauge records spanning 2020 to 2024 are analysed to characterise tidal range, tidal constituents, and diurnal versus semi-diurnal patterns using harmonic analysis. The study additionally integrates real-time acoustic Doppler current profiler data from three transects across the main navigable channel to quantify tidal current velocities and directions during flood and ebb phases. Water depth profiles are mapped using single-beam echo sounding to identify potential shoaling areas. Interviews with port pilots, hydrographic survey officers, and vessel masters are conducted to document operational challenges attributed to tidal constraints. The study finds that the Calabar channel exhibits a predominantly semi-diurnal mixed tidal regime with significant seasonal modulation related to Cross River freshwater discharge during the rainy season. Restricted tidal windows limit the transit of deep-draught bulk carriers, resulting in cargo delays and economic losses. Recommendations include the development of a real-time tidal prediction service for port users and periodic dredging of critical shoal areas. Keywords: tidal patterns, Calabar Port, estuarine navigation, tidal harmonic analysis, port hydrography