The operating environment of merchant ships is dynamic and complex. Particularly, their engine rooms and bridges have complex structures that contain various equipment. In addition, there is the human factor that manages all this complex structure. The systems on-board ships involve interactions between crew, hardware, and software (man-machine interfaces). As a consequence of the growing complexity of socio-technical systems, traditional accident analysis methods are getting inadequate to analyse the complex systems. The conventional analyses are focused on the chain of events and they have limited ability to overcome non-linear interactions among dynamic and complex system components in maritime transportation. The aim of this paper is to apply a Systems Theoretic Accident Model and Process (STAMP) model for the analysis of a ship allision accident occurring in. narrow waters. This is to create a wider view of the accidents rather than a simple chain of events. With the help of detailed STAMP analysis, the dynamic nature of the system, errors in the entire structure, including the human, machine, and software interactions can be analysed. The model also identifies violations of safety constraints at all levels of the control structure, even though the accident involved a complex and dynamic process. The results demonstrate that complex system accidents are not a simple cause-effect chain of events, on the contrary, they are system-based, dynamic, and complex situations. Consequently, the paper tried to reveal all the causes of the Vitaspirit Allison, rather than just one component.