Which action should the diver perform in response to a signal that calls for ventilating?

• A. Stand by to come up
• B. Take up my slack
• C. Ventilate
• D. Circulate

Answer: (C)

When a signal calls for ventilating, you respond by delivering air to the other diver—ventilating means giving breaths through your regulator (or via buddy-breathing) to support a diver who isn’t breathing adequately. The action is about actively providing air, ensuring the airway is open, and the diver receives breaths. So you would start delivering breaths, monitor for chest rise, and continue as needed while staying safe and prepared to adjust to the situation. The other options don’t fit: standing by to come up is about ascending, taking up slack relates to line handling, and circulating isn’t the act of giving breaths to a diver in need.