Final answer:
There is no specific flag that universally signifies a 'man overboard' situation. Historically, flags like the 'baucans' had different meanings, such as signaling battle readiness. Modern maritime distress signals include combinations of visual and auditory cues but lack a dedicated man overboard flag.
Step-by-step explanation:
A man overboard situation aboard ship is indicated by specific distress signals, which can vary depending on the signaling methods available on a vessel. Traditionally, various methods could be used to signal distress, such as flags, flares, or lights. Today, the International Maritime Organization (IMO) prescribes standardized signals for such emergencies, including both visual and auditory signals.
However, there is no specific flag that universally signifies a 'man overboard' situation. In historical contexts, flags had different meanings. For instance, from the 13th century, a 'baucans', which was a plain red streamer, was flown to indicate a ship's intention to engage in battle rather than to signal a man overboard.
To signal distress or emergencies aboard ships in modern times, maritime protocols typically include a combination of alarm signals, such as the Morse code signal SOS, continuous sounding of the ship's whistle, and the deployment of a man overboard marker or lifebuoy. Visual signals like flag November (a blue and white checkered flag) over flag Charlie (blue, white, and red vertical stripes) are used to indicate a diver down, which would, to an extent, relate to a person in the water, but not specifically a man overboard.