What is the first step in the emergency procedure for a lost diver?

The initial step in the emergency procedure for a lost diver is to perform a 360-degree visual search. This action is critical because it allows the diver or the dive team to assess the immediate surroundings for any signs of the missing diver. Engaging in a visual search maximizes the chances of locating the diver quickly, as they may still be within sight or just beyond the immediate area.

This search should be methodical and cover all directions to ensure that no potential sightings are missed. Conducting a visual search first is essential because it is the least invasive action and can provide immediate results.

Following this initial search, further steps would involve notifying the support craft or potentially ascending, but it is crucial to attempt to locate the diver visually before escalating the situation or altering the dive profile. The other options become relevant depending on the results of the visual search and the circumstances surrounding the lost diver situation.