Scuba divers or snorkelers should display a diver-down flag that marks their diving area. Vessels must reduce speed to “no wake speed” while within 100 feet of the flag.
Two types of flags are used to indicate diving activity.
Scuba divers and snorkelers should not place a flag in an area already occupied by other boaters or where their diving operation will impede the normal flow of waterway traffic. Divers also should follow all of the water safety rules themselves.