Scuba diving offers an appealing way to visit underwater destinations. Since you can’t breathe naturally while underwater, you’ll need an external air supply. Unless you’re using a hookah system, with surface-supplied air using long hoses and a compressor, you’ll need a pressurized metal air tank that’s filled before your dive. With careful planning, this air supply will last through your dive’s duration.
Regulator Operation
To breathe underwater, you’ll need a regulator, a device that attaches to your air tank and has two long hoses. The regulator’s first stage converts high-pressure tank air to a lower pressure, and delivers it to your air hoses. At the end of each hose, you’ll find the regulator’s second stage, a mouthpiece that delivers air to your mouth at the proper pressure for your needs. The Professional Association of Diving Instructors (PADI) notes that you actually have two second stages. The second device can help your buddy or another diver if she suddenly needs air.
Enriched Air
As an alternative to standard compressed air, some divers breathe an oxygen-nitrogen mixture called enriched air, or nitrox. Nitrox includes more oxygen and less nitrogen, which means less nitrogen is absorbed into your system during your dive. With less nitrogen in your system, you’ll theoretically be able to stay longer at 50- to 100-foot depths. Because increased oxygen percentages cause concern about central nervous system effects, you’ll need to take an enriched air specialty diving course to learn how to complete these dives safely, according to Aquatic World.
Dry Air Dehydration
Your scuba tank’s air is designed to be very dry, as the air’s moisture has been removed to minimize air tank and regulator corrosion. In addition, every breath exhaled through your regulator expels more moisture from your body. To combat this moisture loss, ScubaDiving recommends you drink plenty of water before and after your dives. Limit coffee and caffeinated soda. Caffeine is a diuretic that draws moisture from your body and compounds dehydration.
Warning
When you’re preparing to ascend to the surface after your dive, remember that you must continue to inhale and exhale normally as you swim upward. The CDC notes that if you ascend while holding your breath, the expanding gas will eventually overwhelm your lungs’ physical boundaries. This can result in a collapsed lung, arterial gas embolism or other pulmonary injury.
Air Supply Emergencies
Some scuba diving problems represent minor inconveniences, but an out-of-air occurrence is a true emergency. Although faulty equipment is a possible cause, in many cases you’ve neglected to check your air supply until it’s too late. Your immediate solution is to locate your small auxiliary air bottle, or your nearby dive buddy’s spare regulator. If neither of those options is available, do a controlled surface ascent while you exhale, Scuba Diving Pro suggests. Bang on your tank to let other divers know you’re in distress. In some cases, more air becomes available as its pressure decreases near the surface.
References
- Professional Association of Diving Instructors: Your Scuba Diving Regulator
- Aquatic World: PADI Enriched Air Diver
- Scuba Diving: No More Scuba Dry Mouth!
- Centers for Disease Control and Prevention: Scuba Diving: Diving Disorders: Pulmonary
- Scuba Diving Pro: 15 Worst-Case Scenarios for Scuba Divers: Out of Air
