Final answer:
A boat engaged in diving operations should fly the A International Code Flag (white and blue), indicating there are divers in the water and other vessels should keep clear and navigate at slow speed for safety.
Step-by-step explanation:
A boat engaged in diving operations should fly a A International Code Flag (white and blue), also known as the alpha flag. This flag is intended to indicate to other boaters that the vessel has divers down and to warn them to keep clear at a safe distance and proceed at slow speed. It is important for boaters to recognize this flag for the safety of the divers in the water. The red flag represents the divers in the water and alerts other boaters to give them space. It is also a signal for other boats to slow down and proceed with caution. By flying the red flag, the boat is indicating that there are divers in the water and that extra care should be taken.