[SIZE=-1]It's no longer just a flag, now they include a bouy.
327.331 Divers; definitions; divers-down flag or buoy required; obstruction to navigation of certain waters; penalty.
[SIZE=-1][SIZE=-1](1)
[/SIZE](b) “Divers-down buoy” means a buoyant device, other than a vessel, which displays a divers-down symbol of at least 12 inches by 12 inches on three or four flat sides, which is prominently visible on the water’s surface when in use.
(c) “Divers-down flag” means a flag that meets the following specifications:1. The flag must be square or rectangular. If rectangular, the length must not be less than the height, or more than 25 percent longer than the height. The flag must have a wire or other stiffener to hold it fully unfurled and extended in the absence of a wind or breeze.
2. The flag must consist of a divers-down symbol on each side with a white diagonal stripe that begins at the top staff-side of the flag and extends diagonally to the lower opposite corner.
3. 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.
4. 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.
(d) “Divers-down symbol” means a rectangular or square red symbol with a white diagonal stripe. If rectangular, the length must not be less than the height or more than 25 percent longer than the height. The width of the stripe must be 25 percent of the height of the symbol.
(e) “Underwater breathing apparatus” means any apparatus, whether self-contained or connected to a distant source of air or other gas, whereby a person wholly or partially submerged in water is enabled to obtain or reuse air or any other gas or gases for breathing without returning to the surface of the water.
[SIZE=-1](2) All divers must prominently display a divers-down flag or buoy in the area in which the diving occurs, other than when diving in an area customarily used for swimming only. A divers-down buoy may not be used or displayed onboard a vessel.
[/SIZE]
[/SIZE]http://www.leg.state.fl.us/Statutes/index.cfm?App_mode=Display_Statute&Search_String=&URL=0300-0399/0327/Sections/0327.331.html
[/SIZE]