Question

Ba-20 the blue and white “alpha” flag signifies what?

Answer 1

If you see that, then it means that a dive boat that is restricted in its ability to maneuver. The restriction is not defined, just that you should be cautious because the boat has troubles maneuvering or cannot maneuver at all for various reasons.

Answer 2

Federal law requires that scuba divers or snorkelers on federally controlled waters display the Alfa diver-down flag to mark their diving area. There are 2 flags used in the world to indicate that divers are in the water.

One of them is a blue and white International Code Flag A, Alfa flag, at least 3.3 feet high and visible from every direction, must be showed on containers whenever these vessels are restricted in their aptitude to maneuver by the diving operation. This flag indicates that the vessel is intricate in a diving activity.