Snorkels over 15 inches in length are not recommended primarily because

• A. They are expensive
• B. They have too much dead air space
• C. They are heavy
• D. They are fragile

Answer: (B)

Long snorkels create a larger dead air space—the portion of air in the tube that isn’t refreshed with each breath. When a snorkel is longer, more of the air you inhale is the air you just exhaled, which has higher carbon dioxide and lower oxygen. That means you have to work harder to breathe, and you can feel lightheaded or fatigued from rebreathing stale air. Shorter snorkels minimize this dead air space and make breathing easier, which is why longer tubes aren’t recommended.