When are decompression dives allowed according to policy?

Decompression dives are conducted under strict guidelines to ensure the safety and health of divers, as the risks associated with these dives can be significant. The correct response emphasizes that such dives should only occur when absolutely necessary and with appropriate authorization. This requirement is not only a matter of operational policy but also a critical safety protocol designed to mitigate the risk of decompression sickness, which can be life-threatening.

By requiring authorization for decompression dives, the policy ensures that a qualified supervisor has assessed the situation and deemed it truly necessary based on the dive parameters and conditions. This promotes a culture of safety and accountability within dive operations, aligning with best practices for underwater operations.

In contrast, the other options imply a level of freedom or leniency that contradicts established safety measures. Allowing divers to proceed with decompression dives at their discretion would undermine the oversight and structured decision-making required in diving operations. Thus, it is critical that these dives are carefully controlled, only to be carried out under specific circumstances where the risks can be managed effectively.