What capability do self-propelled submarines possess?

Self-propelled submarines are designed with advanced features that allow them to operate independently beneath the surface of the water. One of the key capabilities of these submarines is their combat function, which enables them to fulfill various military roles, including reconnaissance, offensive operations, and defense. The residual combat capability means that even if a submarine is primarily focused on other missions, it retains some level of readiness for combat situations.

In contrast, submarines that are solely equipped for scientific research or transportation would not possess the combat tools or systems needed for military operations, indicating a limitation in their functionality. Similarly, submarines restricted from having any combat functions do not align with the operational design of most self-propelled submarines, which are built to support a range of military objectives. Hence, the designation of having at least a residual combat capability is accurate for the classification of self-propelled submarines.