Which of the following is NOT a recognized method of searching?

The method of searching that is not recognized is waiting for volunteers. This approach lacks a structured or systematic strategy and can lead to disorganization or the risk of further complicating a search operation. In emergency situations, relying on spontaneous volunteer participation does not guarantee effective coordination or safety for all involved, especially in high-risk environments like water rescue scenarios.

In contrast, the other methods listed are systematic and have proven to be effective in search operations. Probing underwater involves systematically checking areas likely to conceal a victim, which can yield actionable results. Using sonar or thermal imaging cameras (TIC) allows for advanced detection capabilities that can locate objects underwater or identify heat signatures, enhancing the efficiency of searches. Human chains are a coordinated effort where rescuers link arms to search along a specified area, maximizing coverage while ensuring safety through teamwork. Each of these recognized methods contributes to a more structured and effective search, unlike the more passive and unpredictable approach of waiting for volunteers.