Navigational Risk Assessment for Tanker Traffic in the Lagos-Apapa Port Approach Channel

The Lagos-Apapa port approach channel is one of the busiest maritime corridors in sub-Saharan Africa, handling crude oil tankers, bulk carriers, container ships, and LNG vessels under conditions of high vessel density, strong tidal currents, and limited channel width. This study conducts a quantitative navigational risk assessment for tanker traffic in the port approach channel, applying the International Maritime Organization formal safety assessment methodology adapted for the Nigerian context. Vessel traffic data including Automatic Identification System records for 2022 to 2024 are analysed to characterise traffic density, vessel type distribution, speed profiles, and encounter frequency within the channel. Hydrodynamic modelling using a calibrated Delft3D-FLOW model provides channel current and depth data for varying tidal phases. Human factors interviews with 25 active Lagos port pilots examine operational challenges, near-miss incidents, and communication protocols. Historical accident and incident data from the Nigerian Maritime Administration and Safety Agency are analysed to identify patterns in grounding, collision, and allision events over the past decade. Monte Carlo simulation is used to estimate annual collision and grounding probability under current traffic conditions. Risk matrices compare individual and societal risk levels against international tolerability criteria. The study identifies the No. 2 bend and the outer bar crossing as highest-risk locations. Recommendations include mandatory vessel traffic service coverage expansion, tide window restrictions for deep-draught tankers, and enhanced channel marking. Keywords: navigational risk, tanker traffic, Lagos Port, formal safety assessment, port hydrodynamics