Which CASREP category would prevent a ship from getting underway or accomplishing its mission?

The C-4 category of CASREP indicates that a ship cannot accomplish its mission and is typically associated with conditions that prevent the vessel from getting underway. This situation arises when the damage or malfunction is so severe that it directly impacts the ship's operational capability, rendering it unable to perform essential functions required for mission readiness.

In naval operations, understanding the ramifications of CASREP categories is crucial for effective maintenance and operational planning. The C-4 designation ensures that appropriate measures are taken to address critical repairs, giving priority to the most severe cases where the ship is significantly hampered in performing its duties.

On the other hand, the other categories, such as C-3, C-2, and C-1, denote less severe impacts on the ship's readiness. C-3 suggests that the ship has reduced capability but can still accomplish certain missions, C-2 indicates the ship has a degraded but still workable operational status, and C-1 typically signifies minor equipment failures that do not significantly impair the ship's ability. Thus, C-4 stands out as the category specifically reserved for situations where both getting underway and mission accomplishment are severely affected.