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October 2001 Vol. 16, No. 10   RSS Feed for Undercurrent Issues
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A Better Snorkel?

from the October, 2001 issue of Undercurrent   Subscribe Now

What would you think about a claim that says a snorkel delivers more fresh (fully oxygenated) air than other snorkels, because it has separate chambers for intake and exhaust? Or that a typical diver using a conventional snorkel rebreathes almost 40 percent exhaled, or “used,” air with every breath? That’s the claim for the AirTech snorkel on the website which they support by citing a study conducted at the Henry Ford Hospital’s Human Performance Lab in Detroit, MI.

Ever wary about studies used to hype diving equipment, we contacted the researcher, Frank Fedel, an American College of Sports Medicine-certified Exercise Specialist. Our first question was to find out whether the study was independent, or whether AirTech was behind it.

Fedel, who is a triathlete and freediver, told us he had seen the hype for the Fresh Air snorkel and decided to test it himself. He selected four single-barrel designs, ranging from Oceanic’s $48 Cobra to a straight-tube children’s model.

Hooked to a metabolic monitor, his subjects tested each snorkel in a different sequences, from first, when divers are fresher, to last, when more carbon dioxide has built up. That’s as close to a blind study as he could get, given that snorkels are pretty tough to disguise.

Results, he says, were impressive. Exhaled carbon dioxide levels were 23 percent higher with the conventional snorkels than with the Fresh Air. Average oxygen concentration in exhaled air was about 16.2 percent with the Fresh Air, while the others averaged only 13.9 percent.

Fedel concluded that subjects rebreathed significantly less oxygen-depleted exhaled air with the Fresh Air snorkel than with conventional designs. He sees this study, however, as only a pilot study, and approached Fresh Air to fund a larger study, but they said they could not afford it.

The Fresh Air design is quite simple. The snorkel barrel has a dividing wall from the mouthpiece to two downward facing valves. During inhalation, the valve at the tip opens, letting in fresh air. At the same time, the suction from inhalation seals the other valve tightly so no air can get into that chamber. Upon exhaling, the exhaust valve opens and the exhale pressure further seals the intake valve so all the exhaled air goes out the exhaust valve.

Other features include a cap with downward facing ports to help prevent wave intake and a purge valve that keeps water from backflowing into the mouthpiece.

Air Tech claims the benefits to freedivers include reduced fatigue, decreased hyperventilation, and lower respiratory rate. Many dive shops carry the snorkel, or you can order it through Air Tech, or send $49 to Air Tech, 1200 Holden Ave., Milford, MI 48381.

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