Which of the following is NOT a recognized distress signal?

The choice indicating that a flashing white light is not a recognized distress signal is correct because, while light signals can be used in signaling situations, a flashing white light does not specifically indicate distress in maritime communication.

In maritime contexts, recognized distress signals include specific visual and sound signals designed to convey urgent messages of need for assistance. Red star shells are used in both military and civilian contexts to indicate distress visually. A continuous fog horn is also an established sound signal indicating a vessel is in distress, particularly in situations of reduced visibility. The black square is another recognized distress signal under the International Code of Signals, commonly understood to indicate distress situations.

On the other hand, while a flashing light can be used to get attention, it is not standardized as a distress signal under the same protocols as the other options listed. Therefore, it fails to convey the urgent need for help as effectively as the recognized signals do. Understanding these conventions is crucial for effective communication and safety at sea.