What is the best way to descend in limited visibility or at night?

Descending by using a line is the best approach in limited visibility or at night because it provides a reliable reference point that helps divers maintain their orientation and prevent disorientation as they descend. In conditions where visibility is hindered, divers may struggle to see where they are going, making it easier to lose sight of the entry point or become confused about their depth and direction.

A line allows divers to feel their way down safely, as they can maintain tactile contact, which is especially crucial when surrounding visibility is poor. This technique helps prevent the potential for accidents or getting lost underwater, as divers can always follow the line back to the surface or to a predetermined depth.

Using a surface marker buoy can be helpful for indicating a diver's position on the surface to a boat or support team but does not aid in the descent process itself. Descending straight down may lead to disorientation since divers could lose track of their surroundings. Free diving offers no physical reference and could additionally lead to potential hazards such as rapid ascents or descents without proper buoyancy control or visual cues. Thus, using a line is the most reliable and safest method for descending in such conditions.