BOATsmart! USA Knowledge Base

Module 06 - Other Water Activities Emergency Preparation

Diving and Snorkeling Requirements

With the diverse water ‘playgrounds’ that each state has to offer, exploring the underwater world is a fantastic experience! Just remember, whether you’re diving in a river, a lake or in the ocean, you must always follow the Coast Guard’s Navigation Rules and each state’s requirements for the display of Diving Flags.

Recognizing Diving Flags

Diver’s Flag: A floating red and white Diving Flag (carried on the top of a white buoy) marks an area where diving is in progress. Avoid these marked areas and understand that many states have minimum distance requirements that you must follow.
Alpha Flag: The boat from which divers are diving may display the blue and white Alpha Flag. This flag advises other boaters to proceed with caution because a diver is down in the area. Understand that this flag does not work as a substitute for the Diver’s Flag in those states that require a Diver’s Flag and it does not indicate the exact location of the diver.

The Navigation Rules require boats with night divers to display three, all-round lights in a vertical line. These lights must be located in a position where they can best be seen. The three light colors must be as follows: Red on top, white in the middle and red on the bottom.

Remember that divers may drift away from the area marked by their Diver’s Flag. Underwater currents can move them or they may simply swim out of their zone. Always exercise extreme care by slowing down and staying well clear of areas where you spot Diving Flags.