Which factor is essential for ensuring safety during night dives in limited visibility?

Using more than one light source is essential for ensuring safety during night dives in limited visibility because it significantly enhances a diver's ability to see and navigate the underwater environment. In low-light situations, visibility can rapidly decrease, making it difficult to identify landmarks and potential hazards. Having multiple light sources ensures that if one light fails, the diver will still have another source to rely on, which is crucial for maintaining situational awareness and safety.

In addition to visibility, multiple lights can help communicate with dive buddies, allowing for safer navigation and coordination. This redundancy also helps create a sense of security, knowing that divers are not solely reliant on one device. The distractions or dangers that may be more pronounced during night dives—such as poor visibility, potential for disorientation, or encounters with marine life—make dependable lighting even more critical.

Other factors, while important, do not provide the same level of safety assurance during night dives. For instance, knowledge of the area is beneficial but does not substitute for sufficient visibility; a thicker wetsuit may be comfortable but doesn't address visibility issues; and while a handheld compass aids in navigation, it is ineffective without adequate light to read it and maintain orientation. Thus, using multiple light sources is the most reliable way to enhance safety during