Which flag indicates scuba diving or snorkeling activity?

The flag that indicates scuba diving or snorkeling activity is a red flag with a diagonal white stripe. This flag serves as a visual signal to boaters that there are divers in the area, and they should exercise caution and maintain a safe distance. The red color signifies that there is a presence of a potential hazard, while the diagonal white stripe indicates that diving is taking place.

This flag is part of standardized safety protocols to help protect divers from boat traffic and to make other water users aware of the activity in the vicinity. Understanding and recognizing this flag is crucial for ensuring safety on the water for both divers and boaters alike.

The other flags mentioned do not specifically indicate diving activity and serve different purposes or represent different conditions in the marine environment. For instance, the blue flag with a white circle is often associated with swim areas or designated swimming zones, while the yellow flag with black stripes is typically used to signal caution in the water, and the green flag with a white square may indicate the absence of significant hazards.