The minimum size for any divers-down flag displayed on a buoy or float towed by the diver is 12 inches by 12 inches. The minimum size for any divers-down flag displayed from a vessel or structure is 20 inches by 24 inches.
Any divers-down flag displayed from a vessel must be displayed from the highest point of the vessel or such other location which provides that the visibility of the divers-down flag is not obstructed in any direction.
All divers must prominently display a divers-down flag in the area in which the diving occurs, other than when diving in an area customarily used for swimming only.
Divers must make reasonable efforts to stay within 300 feet of the divers-down flag on all waters other than rivers, inlets, and navigation channels. Any person operating a vessel on waters other than a river, inlet, or navigation channel must make a reasonable effort to maintain a distance of at least 300 feet from any divers-down flag.
All divers must prominently display a divers-down flag in the area in which the diving occurs, other than when diving in an area customarily used for swimming only.