Dive Flags 101: How to Use the Virtual Dive Flag on KnowWake

Dive flags are an important piece of safety equipment not just for scuba divers and snorkelers, but for all boaters and water enthusiasts—including kayakers and personal watercraft users.

What is a Dive Flag?

Dive flags, also called diver down flags, are a simple way to let other vessels in the area know that there are divers nearby and below. That way, those other vessels are made aware to maintain a safe distance of at least 300 ft. from the flag if in open water, or at least 100 ft., if navigating in an inlet or channel—as recommended by the Divers Alert Network (DAN). Likewise, divers and snorkelers should stay within 150 ft. of the flag.

KnowWake users can now deploy a virtual dive flag right in the app, but before we dive into how that works (no pun intended), let’s take a closer look at how to use and spot a physical diver down flag while out on the water.

two types of diver down flags - diver down and alpha

What Does a Diver Down Flag Look Like?

There are many different ways to deploy or display a dive flag, regardless of vessel type. Many boaters fly their flag off of a staff or pole on the boat itself in a prominent position—ideally at the vessel’s highest point. According to DAN, the flag should be at least 20 inches by 24 inches.

Another option is to place your dive flag on a float or buoy in the water. If deploying a flag using this method, the most important thing to keep in mind is that the flag must be flown high enough on its pole so that approaching vessels can see it above waves or choppy waters. The float also needs to be buoyant and stable enough to sufficiently support the flag and its pole so it does not topple over. Dive flags on floats or buoys should be at least 12 inches by 12 inches.

Two Types of Diver Down Flags

There are two types of diver down flags used both nationally and internationally: the diver down flag and the alpha flag. The most commonly used of the two is the diver down flag, which is a red flag with a white diagonal stripe. The alpha flag, which is internationally recognized, is a blue and white colored pennant tail flag.

It’s recommended that divers and snorkelers use both flags, but it’s important to research in advance which flag is required in your local state or dive location.

virtual dive flag on a phone in the knowwake app

Using the KnowWake Virtual Dive Flag

As a compliment to a physical dive flag, KnowWake divers and snorkelers can now utilize the app’s built-in virtual dive flag. When deployed, this feature displays a safe proximity, notifying other KnowWake users in the vicinity of snorkelers and divers in the water.

To deploy the virtual dive flag, follow these easy steps:

  1. First, make sure you have the most recent version of the KnowWake app downloaded to your iPhone or Android.
  2. Open the app, and click on the bottom right ‘Circle Pin’ icon to access crowdsourced location options.
  3. Select ‘Dive Flag.’
  4. Upon clicking, a new message will display on screen, “Warn other vessels of swimmers in the water.” Click ‘OK.’
  5. Move the dive flag on the chart to set your location.
  6. Finally, click ‘Post.’ Your virtual dive flag is deployed.
  7. To remove, select the dive flag on the chart and click ‘Remove.’

Ready to use KnowWake’s Virtual Dive Flag tool?
Take the first step and download the app today to get started.