The Alpha "A" flag is a navigational signal intended to protect the vessel from collision.
The "alpha flag" refers to a flag that is used to signal that a vessel is engaged in a diving operation. If a diving operation takes place from aboard a pleasure craft, Code flag Alpha or flag A (white and blue) from the International Code of signals which means “I have a diver in the water, keep well clear and at low speed” must be displayed. While navigating, if you see this flag, you must keep well clear of the vessel and the diving site.
It is important for all boaters to be familiar with the meaning of the alpha flag and to know how to respond when they encounter it on the water.
