An enclosed space poses a serious risk to workers since its atmosphere can be oxygen-deficient, polluted or contain flammable and/or toxic gases or vapours. Hence, it is important to keep in mind that an enclosed space should not be entered unless it is absolutely necessary. However, many processes often need the worker to be present in an enclosed space. At this point, great attention should be paid to create and maintain safe working conditions, when entering enclosed space is required. Even though studies have investigated several aspects of enclosed space entry, further research is required to explore the human element role. This is urgently needed, considering that human errors are one of the main reasons for enclosed space entry accidents. Hence, this study has investigated the human element role during an enclosed space entry operation via the enhanced SOHRA method. Three scenarios have been developed to assess HEP values. Beyond that, systematic control measure assignment is provided to reduce HEP values. Hierarchy of control measures are considered to improve entering enclosed space operational safety. Elimination (drone-assisted survey), substitution (IoT), engineering (permit control system-PCS), and administrative control measures (electronic permit) have been proposed. Further, this study results can also provide useful insight for other industries (petrochemical, oil, refinery, gas, agriculture, construction etc.), where the accidents in enclosed spaces taking place. Therefore, the study provides not only a theoretical insight but also practical application to improve the safety of seafarers.