A rectangular red flag with a white diagonal stripe is required on state waters.
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.
Boat Operator Tip
As a boat operator you should:
• Be able to recognize a “diver down” flag, a bright red flag with a diagonal white stripe, floating in divers’ areas.
• Stay the legal distance from a diver down flag. The law varies by state so check with your local authorities.
• Be on the lookout for bubbles breaking the water’s surface. There may be divers below who have strayed from their marked diving area.
When diving from a boat, remember:
• Always display the diver down flag from your dive raft or buoy.
• Carry a whistle to alert boaters of your presence and to warn fellow divers of hazards.
• Have at least one person remain on the boat as an observer or in case of emergency.