How is an enclosed space defined?

An enclosed space is defined as any area that is surrounded by bulkheads and overhead structures, which typically restricts easy access to the outside. This definition aligns with the nature of enclosed spaces found on vessels where the characteristics of being enclosed pose potential hazards, particularly when it comes to ventilation and the safety of personnel.

While the other options mention different attributes, they do not capture the full definition of what constitutes an enclosed space. For example, being well-ventilated or having designed exits does not necessarily mean the space is considered enclosed or meets the specific criteria relevant to safety regulations. Moreover, defining a space solely based on human occupation overlooks critical structural aspects that determine whether or not it is truly enclosed. Understanding the correct definition is vital in ensuring safety protocols are followed when personnel enter such areas, thereby minimizing risks associated with the confined nature of these environments.