Final answer:
Vessels must stay at least 100 feet away from a diver-down flag in open water and at least 50 feet away in inland or narrow waters, although distances may vary by local law.
Step-by-step explanation:
By law, vessels must maintain a certain distance from a displayed diver-down flag to ensure the safety of divers in the water. While specific distances can vary by jurisdiction, the commonly accepted distance is that vessels must stay at least 100 feet away from the flag in open water and at least 50 feet away in inland or narrow waters. It’s important for vessel operators to be aware of and comply with local regulations to protect both themselves and the divers below the surface.