What indicates a water-holding compartment in a boat?

A water-holding compartment in a boat is indicated by the presence of hard-sided ports. These ports are designed to allow for the storage and management of water within specific compartments, such as live wells. Hard-sided ports create sealed areas that help prevent leakage and maintain the integrity of the water-holding capacity of the boat.

In the context of the other options, while a live well is indeed a water-holding compartment, it is not an indicator on its own. Hull fittings refer to numerous structural components that may or may not indicate water-holding capabilities, but do not specifically signify a dedicated compartment. An outboard motor, on the other hand, is primarily a propulsion device and does not relate to the storage of water. Understanding these distinctions helps clarify the specific role that hard-sided ports play in identifying water-holding compartments within a boat.