What is referred to as a "compartment" on a vessel?

A compartment on a vessel specifically refers to the enclosed spaces or "rooms" onboard. These compartments can serve various purposes, such as sleeping quarters, storage areas, machinery spaces, or other functional rooms that contribute to the overall operation and living conditions aboard the vessel. The concept of compartments is vital for managing stability and safety, as they can be sealed off in case of flooding or emergencies to maintain buoyancy.

The other options describe different aspects of a vessel but do not align with the definition of a compartment. For example, vessels that have been submerged refer to a state of the vessel rather than its structural arrangement. The area where safety equipment is stored, while important, is just one type of compartment and does not encompass the broader definition. The central control room is a specific type of compartment but again does not cover all enclosed spaces on a vessel. Thus, the answer pertaining to compartments accurately reflects the general definition and usage in naval terms.