The alpha flag is white and blue flag, with a triangular notch on the free end. The left side of the flag is white and the right side of the flag is blue. The alpha flag is recognized internationally and serves a different purpose from the diver down flag. The flag is flown by a boat whenever the mobility of the vessel is restricted. Other watercraft should recognize that the boat can not move quickly, and should yield the right-of-way to a vessel flying an alpha flag. In the case of scuba diving, a dive boat must stay close to the divers it is tending, and cannot easily move from the vicinity of the people under the water. In many parts of the world, the alpha flag is recognized as an indication that divers are in the area, but the flag has multiple uses and it is advisable to fly both the alpha flag and the diver down flag to avoid confusion.