AEMCA Practice Exam

What occurs during a mask squeeze in diving?

1. The mask floods with water.

2. Relative negative pressure causes petechial hemorrhages in the eyes.

3. The mask becomes too tight and painful.

4. The diver experiences a complete loss of visibility.

The correct answer is: Relative negative pressure causes petechial hemorrhages in the eyes.

During a mask squeeze in diving, relative negative pressure creates a situation where the pressure inside the mask is significantly lower than the pressure outside of it. This pressure imbalance can lead to petechial hemorrhages in the eyes because the increased external pressure can cause small blood vessels to rupture, resulting in tiny red spots. The phenomenon occurs particularly when a diver descends without equalizing the pressure inside the mask, which leads to discomfort and potential injury. The other choices, while plausible events related to diving, do not accurately describe the physiological response associated with mask squeeze. Flooding of the mask generally happens when water enters due to improper sealing or a malfunction, which is not specific to mask squeeze. A mask that becomes too tight and painful is more about improper fitting and adjustment rather than the pressure differential experienced during a squeeze. Lastly, loss of visibility may occur due to flooding or other factors, but it is not the defining characteristic of what happens during a mask squeeze. Thus, the response involving petechial hemorrhages accurately captures the critical aspect of this diving phenomenon.