Diver-Down Flags
No person shall operate a vessel within 300 feet of an official diver’s flag unless tendering the dive operation.
Two types of flags are used to indicate diving activity.
Divers Flag: A red flag with a white diagonal stripe indicates that people are scuba diving or snorkeling underwater in the vicinity of the flag.
Alfa Flag: A blue-and-white International Code Flag A (or Alfa flag), at least 3.3 feet (one meter) high and visible from all directions, must be displayed on vessels on federally controlled waters. This flag indicates that the vessel is involved in a diving activity.