What should divers do to avoid blinding oncoming divers?

When divers are navigating in dark or low-visibility environments, such as caverns or caves, lighting is critically important for both safety and communication. Shielding lights when overtaking oncoming divers is essential to prevent temporarily blinding them. Direct light beams can impair a diver's ability to see their surroundings and can lead to disorientation or even panic.

Using a shield or adjusting the direction of the light minimizes the intensity of the light directed towards oncoming divers, thus maintaining their visibility and comfort. This practice helps ensure that all divers can proceed safely through narrow or shared spaces without creating hazardous conditions.

While the other choices might suggest alternative approaches, they do not adequately address the specific concern of visual blinding when multiple divers are present. Turning off lights completely, for example, can compromise safety by eliminating visibility. By adjusting light intensity, divers might still inadvertently create glare, which can be disruptive. Relying solely on handheld lights may not always provide adequate coverage or visibility, particularly in challenging conditions. Therefore, shielding lights is the most effective method to ensure safe passage for all divers involved.