How should divers use their lights when signaling a dive buddy?

Using flashing lights intermittently to signal a dive buddy is an effective communication method in underwater environments, particularly during night dives or in limited visibility situations. This signaling technique helps to catch the attention of a dive buddy, as it creates a contrasting effect against the surrounding darkness or murkiness of the water. The intermittent flashes are more noticeable compared to a steady beam, signaling that immediate attention is needed or to indicate a problem or alert.

The other options can be less effective for various reasons. A continuous beam can suggest direction but may not effectively attract a buddy's attention in a dynamic environment. Pointing a light downward can limit visibility for the buddy, as it restricts the area of illumination to an area close to the ground rather than making the diver visible. Turning lights off entirely would reduce visibility, making communication and navigation difficult for both divers.