When is a lifeline used in diving operations?

A lifeline in diving operations is essential for maintaining a connection between the diver and the surface support team. This connection is crucial for safety and communication. The lifeline enables the team to monitor the diver's location in real-time and helps in signaling if the diver encounters any issues or emergencies.

In addition to location tracking, lifelines facilitate communication through signals, allowing divers to share important information without relying solely on verbal communication, which can be challenging underwater. As such, lifelines are a primary safety measure, especially in situations where visibility may be poor or when divers are operating in challenging environments.

Other options may suggest specific conditions like night dives, deeper depths, or visibility issues; however, the use of a lifeline is not limited to these scenarios. It is a standard practice in many diving operations to ensure divers remain connected and accounted for, regardless of the surrounding conditions. This makes option B the most comprehensive and accurate answer regarding the use of lifelines in diving operations.