Which of the following physical factors can make you incapable of sustaining efforts sometimes demanded when participating in recreational diving?

• A. Inadequate sleep
• B. Recent head cold
• C. All of the above
• D. Recent ingestion of drugs

Answer: (C)

The ability to sustain the physical effort a diver may need depends on staying physically and mentally sharp, having clean airways and good energy, and avoiding substances that dull performance. Inadequate sleep reduces stamina, slows reaction times, and impairs judgment and concentration, making tasks like buoyancy control, fine motor adjustments, and rapid decision-making harder under pressure. A recent head cold can disrupt breathing, reduce oxygen delivery to muscles, and cause fatigue through increased work of breathing, plus congestion can affect your comfort with pressure changes and equalization, all of which can sap your endurance in the water. Recent ingestion of drugs can dull awareness, slow coordination, and blunt judgment, increasing the risk during ascent, navigation, or emergency responses. Because any of these factors can weaken your ability to meet the demands of a dive, all of the above is the best answer. If any of these conditions are present, it’s wise to delay the dive until you’re fully recovered or free of impairing substances.