The Ultimate Dive Flag Guide for Scuba Divers and Boat Owners

Getting rammed by the hull or worse, the propeller of a stray boat while taking a surface dive stop is probably one of the worst nightmares for scuba divers. That’s where a Dive flag, more prominently known as a diver-down flag, arrives to save the day.

What are Diver Down Flags?

Dive flags serve as essential visual indicators informing boaters about scuba divers’ presence in the water and preventing head-on collisions. It indicates a diving activity is in progress and cautions water traffic to steer clear, slow down, and stay vigilant when passing within 100 feet or more depending on local guidelines. Most boating laws prohibit vessels from approaching within a mandated safe distance of a displayed alpha flag.

Not only that, but your dive flag also lets other boaters know better than to not call the Coast Guard on your (seemingly) abandoned dive boat!

When Is a Diver Flag Necessary?

While specific rules can vary, most regions require divers to mark their location with a diver down flag anytime:

• They are making a vertical ascent directly to the surface after scuba diving, even from relatively shallow depths.
• Diving is occurring farther than 300 feet from shore. Some areas mandate flags whenever beyond 150 or even just 50 feet offshore.

So check your local diving guidelines, but if you will be ascending vertically through the water column within several hundred feet from shore or at any point offshore, deploy that flag!

The Typical Appearance of Dive Flags

Unlike national flags, diver-down flags are usually square shaped, and as per the latest standard, the base of the flag must be bright red with a white stripe running diagonally from left to right. Red is the color with the highest visibility in the color spectrum and white offers the ideal contrast. So, this color combination can be easily spotted in the blue waters from large distances by other vessels and boats.

Although not mandated by law, according to DAN dive flag safety guidelines the standard dimensions of the flag should ideally be at least 12 x 12 inches when placed on a buoy and 20 x 24 inches, when towed to a boat. The diagonal stripe thickness is expected to be 1/3rd or 1/5th the side length.

If you are buying a complete dive flag set the flag comes with a detachable rod to hoist the flag on, along with an inflatable float (often called a buoy) on which you can place the rod.

Prolonged saltwater exposure can weaken standard silk material. Hence dive flags are made with durable nylon or polyester fibers.

Types Of Diver Down Flags Based On Color Combination

There are primarily two types of diver down flags based on the color combination but they both serve almost the same purpose.

While a red flag with a white diagonal stripe is internationally recognized as the standard color scheme of scuba flags, there is another flag known as the alpha flag (sometimes called the alfa flag) with a different color combination that serves the same purpose as a diver-down flag.

The alfa flag features a blue and white colored piece of fabric with a swallow-tailed incision on the blue end. Technically speaking, although alfa flags are sometimes used by scuba divers as a dive flag the original purpose of the alfa flag is not quite the same as the red and white diver-down flag but there is a significant overlap between their intent.

As for the reason behind the emergence of two dive flags, there’s a long history of ownership rights feud. You may want to check out this detailed resource on the history of dive flags at the scuba board forum.

How Is the Alfa Flag Different from The Regular Diver-Down Flag?

For a vessel owner spotting a standard red flag with a white diagonal stripe should imply “There’s a diver in the war within a 100-meter circumference of the flag, please exercise caution.“

The presence of a blue and white alfa dive flag, on the other hand, has a broader implication- “The vessel in the vicinity of this flag is engaged in underwater operations or is inoperable. Please maintain distance and exercise caution.” Underwater operations can mean a lot of things apart from scuba diving. The alfa flag is generally used by research divers and vessels.

As a scuba diver, you can use either the red or blue flag as they essentially serve the same purpose for you. Although, the color red being more flashy, is a better option to catch the eye of boaters from a distance.

Towing Your Dive Flag

A common cautious diver’s dilemma: to tow or not to tow the dive flag? It’s a question that plagues many dive safety regulation nerds in the scuba diving community. So, what exactly is towing?

Towing your dive flag simply means that instead of tying the loose end of your flag buoy’s reel to the end of your boat, you have to tow (drag) it along with you.

Towing your dive flag along makes your immediate underwater location more at par with the surface position of your dive flag to boat operators and your dive buddies on the surface.

While towing seems to be the right choice for a disciplined and cautious diver, there’s a flip side to it too. Dragging your dive flag along can greatly hamper your underwater mobility. The flag line creates extra drag, affecting your buoyancy and overall maneuverability, not to mention the constant struggle to keep the line taut to prevent chances of entanglement.

Those against towing mostly claim that it’s unnecessary and that relying on boat operators to steer clear of the waters surrounding the dive flag is sufficient. While it’s true that responsible boaters should keep an eye out for divers, would you trust your life to the diligence of some random boat operator in the middle of the ocean?

If you’re drift diving at a shallow depth which involves moving away more than 50 meters from your entry point or in inlets or channels with frequent passage of boats, towing the flag along with you is a good safety measure.

Otherwise, you can tie your dive flag to your anchored dive boat and go on about your underwater business. And in that case, you have to be vigilant at all times so that you don’t exceed the dive flag safety circumference.

Ideal Distance To Maintain From A Diver Down Flag

Divers and Snorkelers

As a diver, your safety is in your hands. If you can tow your dive flag along with you, that’s what I would recommend. Otherwise, don’t stray away from your dive flag too much.

DAN recommends that you stay within a distance of 300 feet (90 meters) from your dive flag or surface buoy in open water and 100 feet (30 meters) when diving in rivers, inlets, or navigation channels.

These are the upper limits of safe distance from the dive flag so keeping that in mind, try to stay within this limit. The sweet spot is around 100 feet (that’s 30 meters) from the flag. Make a conscious effort to surface within 50-80 feet of the dive flag.

Boat or Vessel Operators

Make sure to give a wide berth to any diver-down flags you encounter. Be a responsible vessel operator and keep your eyes peeled for any signs of dive flags or surface buoys.

When operating a vessel in areas known for frequent dive activities, if you spot a dive flag the minimum recommended circumferential distance you should maintain from it is 250-300 feet (60-90 meters).

Good Diver-down Flag Practices

• Choose the Right Flag and Float: Invest in a professional-grade diver down flag kit designed for easy transport, quick setup, and reliable marking of your dive spot, complete with a brightly colored float for high visibility even at a distance offshore. Custom options like lights, clips, and reels tailored for easy retrieval and storage between dives are available.
• Check Local Regulations: As mentioned previously, legal requirements for when and where to display diver down flags can vary in different jurisdictions – whether by country, state or even county. Be sure to check the latest guidance for wherever you will be diving.
• Pick the Optimal Location: Ideally, deploy your flag 100 feet up-current from the dive entry/exit location. This accounts for drift and marks where divers will surface. If the current is negligible, position it directly above or adjacent to your entry point.
• Weight Your Dive Flag Properly: Use the weights and lines provided with your flag kit (or improvise equivalents) to anchor the float solidly in position, accounting for wind, waves, and any current. You don’t want your flag drifting away from the dive site!
• Ensure Maximum Visibility: Regardless of the flag type, orient it straight up and completely out of the water for the best all-around visibility at a distance of 360 degrees. If needed, add more individual floats to keep the flag upright and proud.
• Use at All Depths: Even when diving well below the surface, boaters overhead may not see bubbles or other activity marking your group’s presence. Fly that flag high and proud anytime your safety could be at risk!
• Attach Signals for Night Diving: Standard diver down flag kits are designed for daytime use, but if diving at night, attach reflective tape, glow sticks, or strobes to identify your position after dark.
• Follow Retrieval Procedures: When wrapping up your dive, pull up the float line to retrieve your flag rather than letting it drift loose.

Stay Visible, Stay Safe

Using a diver down flag is mandatory in many diving contexts and always advisable whenever entering the water outside very shallow nearshore areas. In the end, remember the golden rule: respect the dive flag and maintain or keep within the recommended safe distance. So, next time you’re out there, keep your eyes on the flag.

An elementary rule to follow that would save you as a diver from being turned into a popped marine watermelon and as a boater help you avoid doing time for mowing down a diver.