The Most Common Causes of Out-of-Air Emergencies

Lack of Awareness

1. Diving too Deep

Gas consumption increases dramatically with depth. Your decompression obligation builds quickly, and you may need more gas for decompression stops. An Aluminum 80 is not meant for deco dives. Running out of gas at depth puts you at risk of a long, hazardous emergency ascent. You can maximize your time at shallower depths and easily reach the surface in the event of an emergency.

2. Staying Too Long

Sooner or later you will consume your gas reserves. Determine in advance the tank pressure at which you will need to turn back and start your ascent. During the dive, actively monitor your tank pressure and turn back on time.

3. Working too Hard

Fighting a strong current, hunting or lacking buoyancy control can affect air consumption. Exertion at depth may speed up depletion of your tank up to twenty times. If you are not accustomed to diving in strong currents or surf, seek training prior to diving in these environments.

4. Not Monitoring Your Pressure Gauge

Be air aware: Monitor your air supply. Check your pressure gauge regularly and communicate your supplies with your buddy.

5. Ignoring Anxiety as a Factor

Anxiety changes all calculations and may deplete tank reserves faster than vigorous exercise. Try to maintain normal breathing, but if you do feel anxious, keep a closer eye on your gas supplies; it may dwindle more rapidly than usual.

Procedural Problems

6. Starting With Less Than a Full Tank

Regardless of how short an immersion you may contemplate, do not start your dive on less than a full tank. Never descend to retrieve a lost piece of equipment or anchor if the tank is nearly empty.

7. Not Opening the Tank Valve All the Way

Open the tank valve all the way and check that breathing through the regulator does not cause the pressure indicator to swing with each breath

8. Frequent Depth Changes and BCD Adjustments

Yo-yo diving, or using your BCD frequently to move up and down in the water column, can quickly deplete your gas supply. Yo-yo diving also increases risk of pulmonary barotrauma and decompression sickness.

9. Omitting Predive Check and Buddy Checks

Use a printed predive checklist to prevent mental lapses—the mental checklist is an oxymoron.

Equipment Issues

10. Regulator

Your gas consumption can be affected if:

  • Your regulator is hard to breathe from.
  • Your regulator starts to free-flow due to freezing or debris.
  • Your dive buddy accidentally knocks your regulator out of your mouth.
  • Your secondary regulator has a slow leak.
  • Your mouthpiece decouples from your regulator.

Take preventive steps:

  • Rinse your regulator after diving.
  • Conduct regular maintenance on your regulator and have all parts replaced that may have been worn off or are out of date.
  • Secure your spare regulator—don’t let it drag on the bottom.

If your regulator starts to free flow, attempt to flush it; this may help if debris is to blame. Remember, you can still breathe from a free-flowing regulator, but the gas will not last long, so you have to initiate the ascent.

11. BCD

Inflator leaks or tears in your BCD can deplete your air. Rinse your BCD after diving and conduct regular maintenance to prevent leaks.

12. Pressure Gauge

If your pressure gauge is integrated with your computer, a computer error may also affect the gauge. If your tank pressure does not decrease with time of dive, you have a problem and should safely terminate the dive. Make sure that your gauge is calibrated properly. Some gauges will not indicate zero, even when the tank is empty. To avoid this problem, make sure you return to the surface with the gauge indicating 500 psi or greater.

13. Burst O-ring or Hose

O-rings should be replaced regularly. Carry your own with you, and if you have a minor leak, replace the O-ring in question. Do not open your regulator on your own; this should only be done by a certified maintenance professional.

Next: Safety Tips to Prevent Out-of-Air Emergencies>