Diver down flag laws vary from one place to the next, and they vary depending on whether you are shore diving or diving from a boat. Let’s take a closer look at the two dive flags used internationally: The red flag with its’ white diagonal strip, and the blue “alpha” flag, which has the same diagonal white stripe. These flags are sometimes, but not always interchangeable. Here is a quick basic guide; be sure that you read and understand the rules for diving with a flag in the places you go.
Understanding Dive Flag Laws
When diving from a boat in the US and in most places internationally, the dive boat is required to display a rigid replica of the alpha flag no smaller than a meter in height. This flag advises other vessels that the dive boat has the right of way. In navigable inland waters, including bays, rivers, and lakes, dive vessels 36 feet long and greater must display a trio of lights arranged one on top of another. The top light is red, the center light is white, and the lower light is red. Think of the colors of your dive flag, and you’ll always be able to remember this combination. In addition to the lights, dive vessels operating within inland waters must display three shapes; a ball atop a diamond, atop another ball. All these signals must be prominently displayed.
In some places, boats may only display these signals while they are tending to divers. They may not display the signals once divers have been brought back onboard when the dive has been completed.
When diving in federal marine sanctuaries, ensure you check their laws. Each area has different requirements for vessels tending divers. In addition, when diving in different states, ensure you follow all regulations. Lawyers recommend you comply with both federal and state regulations, even though federal regulations supersede state mandates.
When shore diving, it is also advisable to fly a diver down flag, and to stay within a reasonable distance of it. Laws vary from one state to another regarding the distance a diver may stray from his or her flag, and the mandated minimum dive flag size varies as well.
In the United States, a “Diver Down” flag is either a red square or rectangle with a diagonal white strip extending from the upper left corner to the lower right corner; most are rigid so that they can be spotted even when the wind is not blowing. Boats are required to yield to this flag and stay certain distance away from it; this, combined with requirements for divers to stay within a certain boundary, is intended to prevent diver injury or death via prop strike.
Flouting laws regarding dive flags can result in serious fines for vessel operators and divers both. A good practice to follow is to prominently display both the alpha flag and the diver down flag, no matter where you are diving. Besides giving boaters a clear signal that states divers are in the water, this practice will put you in compliance of most state, federal, and international laws.