Gompertz Distribution Modeling of Vessel Characteristics and Maritime Accident Propensity in West African Territorial Waters

Abstract

This study investigates vessel characteristics associated with maritime accident propensities in West African territorial waters, focusing on ship type, size, and purpose, and their interactions with flag state, accident location, accident types, and casualty characteristics. The aim is to provide empirical evidence for targeted safety measures and policy interventions in the region. Using a survival analysis framework, the study analyzed maritime accident data from 1997 to 2022, employing six survival distribution models: Cox proportional hazards, Gompertz, Weibull, lognormal, loglogistic, and exponential. Model selection was based on log-likelihood values’ goodness-of-fit criteria. The analysis also incorporated reparametrized interaction effects to assess the joint influence of flag states, accident locations, accident types, causes, and casualty degrees on accident risk. Vessels were stratified by tonnage (100 to 100,000 tons), and discrete vessel types and ship purposes were systematically examined. The Gompertz distribution model emerged as the most suitable for the dataset. Results indicated that ship type was statistically significant (α = 5%), with fishing vessels showing a 6.5-fold increase in accident risk compared to other vessel types. Smaller tonnage vessels (100 to 1,000 tons) were more prone to accidents. Interaction effects revealed that flag states and casualty degrees were statistically significant (α = 5% and 1%, respectively). Vessels registered in Nigeria and operating under 1,000 tons exhibited a lower hazard ratio, while Nigerian-flagged fishing vessels were significantly more accident-prone. Capsizing and parted mooring ropes were critical risk factors for smaller vessels, particularly under adverse environmental conditions. The findings highlight the significant role of vessel characteristics, particularly ship type and tonnage, in maritime accident risk in West African waters. By employing survival models, the study provides a robust methodological approach to maritime risk assessment, offering insights for enhanced safety protocols and policy formulation. Targeted interventions could prioritize smaller and fishing vessels, with attention to interactions among flag state, accident location, and casualty severity. These results underscore the need for West African region-specific maritime safety protocols to mitigate risks and improve overall maritime safety.