What is the chief concern for divers when diving at night?

Reduced visibility is the primary concern for divers when diving at night. When it is dark, natural light is significantly diminished, making it difficult for divers to see their surroundings and any potential hazards. This lack of visibility can impact a diver's ability to navigate, identify marine life, and communicate with buddies. Divers must rely more heavily on artificial light sources, such as dive lights, to illuminate their path and ensure they can see objects clearly.

In many cases, the underwater environment can appear quite different at night, with colors and shapes altered or obscured. This can lead to an increased risk of disorientation or encountering obstacles that may not be as visible during the day. Therefore, divers need to be well-prepared with appropriate lighting and techniques to manage reduced visibility effectively.