How should communications be established and maintained during the dive?

• A. Use tested surface-supplied communication systems (voice or line signals), confirm procedures, and maintain continuous contact with divers and standby.
• B. Use only visual signals from the boat and ignore line signals.
• C. Rely on postdive debrief for all communication.
• D. Use modern cell phones underwater to talk to divers.

Answer: (A)

Communications during a dive should be established and maintained with reliable surface-supplied systems that are tested beforehand, with clear procedures confirmed prior to descent, and with continuous contact maintained between the surface team, divers, and the standby diver. This setup allows immediate two-way communication, whether it’s a voice channel through the diver’s umbilical or a recognized line-signal system, so instructions, status updates, air supply concerns, changes in plan, or emergencies can be conveyed quickly and unambiguously. Having confirmed procedures means everyone knows what signals mean, what actions to take, and what to do in contingencies, reducing the chance of miscommunication under stress. Keeping a continuous link ensures the supervisor can monitor divers’ status and intervene or adjust plans without delay.

Relying solely on visual signals from the boat or on postdive debriefing, or trying to use underwater cell phones, is not appropriate. Visual signals alone may be misread or missed, and they don’t provide the full two-way communication needed for real-time decisions. Postdive discussions happen after the dive and don’t support immediate safety actions during the dive. Cell phones don’t work underwater and aren’t designed for dive environments, making them unreliable for maintaining critical communication.