What should a diver do to locate a missing buddy?

When a diver is trying to locate a missing buddy, holding the light straight out and making two 360° turns is an effective method. This action serves two purposes: it maximizes the visibility of the light in all directions, which can help attract the attention of a buddy who may be nearby, and it allows the diver to observe the surroundings for any signs of the missing buddy.

By illuminating a wider area and performing a complete turn, the diver can effectively scan the environment for any movement or reflective surfaces that might indicate the presence of the buddy. This technique is particularly useful in low visibility or night diving conditions, where visual cues are limited. The other options may not provide the same level of visibility or opportunity for detection, making this method the most suitable for locating a missing buddy in these specific diving scenarios.