A dive flag warns boaters that scuba divers are in the area. In most states and countries, the use of a dive flag is required by law. If diving from a boat, you can fly the flag from the boat providing you stay in the immediate vicinity of the boat. Otherwise you will fly the flag from a float that is towed by you, using tow line and a reel.
Since rules and regulations vary from state to state and location to location, make sure you have the locally recognized dive flag. You will either need the red and white diver-down flag or the blue and white Alpha flag. If you’re not sure which flag you will need, contact your local dive shop for assistance. Should you have no way to tell which flag you need to use, get both flags and fly them both.
The size of diver-down flags displayed on vessels has been increased from 12" X 12" to 20" X 24" and requires a stiffener to keep the flag unfurled. Dive flags carried on floats may still be 12 inches by 12 inches.
Dive flags on vessels must be displayed so that visibility to the flag is not obstructed.
Flags are also required for beach entry divers.
Vessel operators must make reasonable efforts to maintain a distance of 100 feet from any divers-down flag while on a river, inlet, or navigation channel; divers must make a reasonable effort to stay within 300 feet of the divers-down flag on all waters other than rivers, inlets, or navigation channels; vessel operators must make a reasonable effort to maintain a distance of 300 feet from vessels displaying dive flags on these waters.
Divers shall attempt to stay within 100 feet of the divers-down flag on rivers, inlets and navigation channels.
Vessels may approach within 100 feet or 300 feet of a divers-down flag at idle speed.
"Buzzing" a dive flag has been added to the description of reckless operation of a vessel, which is a first degree misdemeanor punishable by a fine up to $1,000 and/or up to 6 months in jail.
Divers shall not, except in case of emergency, display the divers-down flag in an area which would constitute a navigational hazard.