The failure to identify the hazards, assess the risks and implement an appropriate procedure to entry enclosed spaces on board has been proved the main cause of many accidents occurred on board. Therefore it is imperative that only trained and authorized personnel should be assigned the duties of entering enclosed spaces as strongly recommended by the RESOLUTION MSC.581(110) adopted on 27 June 2025. The GMS course “Enclosed Space Entry” gives the required training and the necessary familiarization for a sound management.