PADI Divemaster Certification Practice Exam

Which of the following statements about shallow water blackout is true?

1. It only occurs at great depths

2. It is caused by an excess of carbon dioxide

3. It can happen due to hyperventilation

4. It is a safe practice for divers

The correct answer is: It can happen due to hyperventilation

Shallow water blackout is a serious concern for divers, particularly related to hyperventilation. When a diver hyperventilates before a dive, it can lead to an unusually low level of carbon dioxide in the blood, which may deceive the diver into thinking they can hold their breath for a longer period. This can result in a loss of consciousness underwater before the diver feels the urge to breathe, leading to shallow water blackout. In this context, the recognition of the risk associated with hyperventilation is critical. It highlights the importance of maintaining proper breathing techniques and being aware of one’s physiological responses while diving. Understanding the mechanism behind shallow water blackout can enhance diver safety and help prevent dangerous situations. In contrast, the incorrect options misrepresent key aspects of shallow water blackout. For instance, it can occur at various depths, and it does not relate to excessive carbon dioxide but rather to its low availability due to hyperventilation. Additionally, it is certainly not a safe practice; rather, the awareness of hyperventilation's dangers is essential to ensuring safety during dives.