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Diver Down Flags Explained
Divers float coloured flags at the surface of the water to alert boat traffic about their presence below and they may soon be making an ascent.
This guide explains how to use the red and white "diver down" and the blue and white "alpha flag" to warn boaters that scuba divers are in the area.
What is the Purpose of Floating a Dive Flag?
The main reason for using one of the recognised scuba flags is to signal that people are below the water or close by, such as:
- Scuba divers
- Breath-hold free-divers
- Spearfishers
- Snorkelers (skin diving)
In fact, flying a dive flag is a legal requirement for divers in some areas - and one of the general scuba diving safety rules and regulations.
You learn why dive boats fly the diver down flag in the PADI Boat Diver course. The purpose is to show other watercraft that divers are in the water.
One simple solution is to attach a flag to an inflatable buoy that will float at the surface. Some divers will use a line and reel to tow it while they're in the water.
Key Features of Dive Flags
- The two flags used for scuba diving safety are the diver down red flag with a white diagonal stripe, and the blue-and-white navigational signal Alpha "A" flag.
- Unless it's flying from a staff or a tall pole (e.g. from somewhere prominent on a boat), it needs to be high enough that other vessels can see it above any choppy waves.
- Floats need to be stable and buoyant - enough to keep the flag and staff upright. You can buy basic inflatable circular-shaped buoys or torpedo shaped floats that make towing easier. In some cases, you may need to use a heavy duty surface support ring (e.g. a scuba buoy safety float with an inflatable bladder inside).
- If you don't anchor the float, towing it with a simple line and reel is quite easy. Some of the scuba accessories used to attach lines to floats, include handles, loops, and stainless steel D-rings.
- In general, different kinds of diving activities will determine what float size and style you need. You may want to use weights, or screw an auger (corkscrew) into the sand or substrate (not delicate coral formations), to anchor the float.
Pro Tip: Divers can use a wire frame stiffener to open up the dive flag and make it more visible. Modern inflatable tube styles provide excellent buoyancy and they have a pouch to store dive gadgets and gizmos (e.g. equipment for spearfishing, or your personal locator beacon).
How to Use Dive Flags
The flag must either be the red-and-white "diver down", the blue-and-white "Alpha", or both, as required by local regulations. Dive flags should be flown stiff and unfurled (open to the wind) and in good condition.
DIVER DOWN FLAG
The flag with a red background and a white diagonal stripe signals that divers are in the water.
Float it at the surface from an inflatable buoy if you are unable to fly it from the highest point of a vessel.
The 'diver down' flag should be a minimum of fifty (50) centimetres (20") by sixty (60) centimetres (24") when flown from a vessel. It should be at least thirty (30) by thirty (30) centimetres when displaying the flag from a buoy.
ALPHA FLAG (PENNANT)
The Alpha "A" flag is recognised internationally when flown from a vessel. It indicates that the vessel has restricted mobility in the water. Thus, other vessels should yield the right of way.
SURFACE MARKER BUOYS
Scuba divers use a surface marker buoy (SMB) to alert boat traffic that they are making their ascent. Plus, audible signaling devices (e.g. a dive light, air horn, mirror, or whistle), will also help to get you noticed and heard by the surface support team (e.g. boat crew).
Pro Tip: The Drift Diving certification warns scuba divers not to assume that all boaters follow local laws. In fact, some boat captains don't even recognise scuba flags. Thus, if you hear a boat, stay down until it leaves the area before you come up - and stay close to your marker. You can report a diving incident online to the Divers Alert Network (DAN).
SAFE BOATING GUIDELINES
The ideal way to prevent diving injuries (and death from propeller strikes), is to make divers and boaters aware of one another.
Boat operators should stay a safe distance from flags used by divers. The drivers should keep a distance of at least ninety (90) metres (300 feet) from diver down flags and buoys in the open water. This minimum distance reduces to thirty (30) metres (100 feet) in navigation channels or inlets.
Here's the thing:
Divers should use diver down and Alpha flags in an appropriate manner. Divers should stay within ninety metres of the diver down flag or buoy in open water and aim to surface within forty five (45) metres (150 feet) of the flag.
Responsibilities for Divers
There are several ways to enhance diver safety in water. Besides making sure you're visible, you must also comply with any regional laws and restrictions.
Have a plan for making an appropriate response for a diver injured by a boat strike or by propeller blades. If there is an incident, follow the guidance on the DAN Emergency Action Plan template for evacuation procedures.
- Always pay attention to the dive briefing and be mindful of boat etiquette and protocols. Wait until someone confirms that the engine is off before entering the water. Follow the recommended safety procedures for entering and exiting dive boats.
- Don't underestimate the importance of establishing a clear communication stream with the operator of the boat and any others onboard.
- It is not safe to assume you are visible at sea level. Use good quality diver down flags to signal your position to boaters and use surface markers buoys at the surface.
- Scan for sights and sounds of boat traffic while you conduct your safety stop. Stay away from the propeller at all times - even if it's disengaged.
Responsibilities for Boat Drivers
Some of the recent scuba diving accidents and incidents show that boat operator inexperience and negligence are contributing factors.
As a boat operator, you should be constantly looking for people in the water. Being attentive and alert are effective ways to prevent severe boating accidents.
- Assuming that divers are always visible is inaccurate and false. For example, visibility becomes much more challenging in choppy seas, from wave action, adverse weather conditions, and the glare of the sun. Ensure you have the appropriate dive rescue equipment to respond to emergencies, including:
- Communication devices (e.g. for PAN PAN radio call)
- Emergency first aid training
- Oxygen units
- Stocked first aid kits
- Observe all safety guidelines and protocols. Make sure the engine is turned off and the propeller is motionless before allowing any divers or swimmers to board or disembark.
- Do not allow people to be anywhere near the swim platform while the engine is in gear. Make sure no one is swimming or diving near or underneath before starting the engine.
- Provide clear instructions for divers and swimmers to stay clear of the propeller blades at all times. In fact, even an immobile propeller can cause an injury.
Pro Tip: Remember to rinse the gear in fresh water after use and keep it stored in a dry place (away from direct sunlight). General maintenance also includes checking the line for any worn or damaged spots - and replace them when it becomes necessary.