What does the orange background with a black ball indicate?

The orange background with a black ball is an internationally recognized distress signal indicating a situation where assistance is required. This specific signal is used within maritime contexts to communicate an emergency or urgent need for help. When vessels encounter this signal, they are alert to the fact that a danger exists, prompting them to respond appropriately by investigating further or contacting authorities.

In maritime navigation, understanding the meaning of various signals is crucial for ensuring safety and effective communication on the water. The other options represent different warning systems or alerts but do not specifically denote a distress situation in the same clear manner as the orange background with the black ball does, which is focused solely on signaling an emergency that requires immediate intervention.