How to Avoid and Deal with Running Out of Air
There’s really no reason you ever find yourself running our or air. As long as you monitor you pressure gauge, and plan your dive correctly you should have enough air to finish a dive after a safety stop and a slow safe ascent to the surface.
What is the difference between running out of air and running low on air underwater?
Running low on air when scuba diving simply means it’s time for you to abort the dive, though you still have ample supply of air to complete the recommended safety stop and to slowly ascent to the surface. Scuba tanks shouldn’t be emptied completely as air pressure inside the tank prevents water and moister from entering it, corroding its interior. We should finish our dive with about 500psi, 35 bar of air pressure in our tank, meaning we need a bit more than that to start aborting our dive. Running Low on air isn’t life threatening, there’s still enough time to finish the dive.
The universal signal for running low on air is a feast held close to the chest.
Running out of air while scuba diving means you’re about to, or completely have finished your air supply and emptied your tank. Running out of air underwater is risky and demands immediate attention and response as will be described later in the article.
The universal sign for running out of air is a clear throat slitting motion.
How to avoid running out of air?
1. Monitor your air pressure frequently.
Some advanced Dive Computers allow you to monitor your tank’s pressure through transmitters attached to the tank. You can also monitor your buddy’s air supply as well using that feature, increasing safety furthermore. Otherwise, just check your pressure gauge occasionaly and follow your dive plan allowing enough time for getting back to the exit point , completing a safet stop and ascending to the surface.
2. Plan you dive properly.
When planning a dive you should limit yourself to the NDLs the No Decompression Limits, but it doesn’t mean neglecting your air supply limitation.
Remember, air consumption is individual and is effected by many variables.
You can roughly estimate air consumption rate using this simple formula:
Air consumption at the surface*(1+depth in m /10)
For example a diver at 20 m, will consume air 3 times faster at 20m:
Surface air consumption*(1+20/10)=S.A.C*3
A good trick is to plan your dive backwards:
A. Allow 40bar / 500psi at the end of the dive, to prevent water and moisture from entering the tank and corroding its interior.
B. Allow some air for a minimum 3 minutes safety stop. (An estimated 20bar/300psi)
C. That leaves about 2200psi/140Bar for the rest of your dive.
D. you can keep adding more elements, such as moving from and away from the exit point (takes about the same time, air consumption varies depending on depth changes) or Multilevel Dive Plan, where at each depths you consume air in deferent rate.
Out of Air Emergency Procedures:
If eventually you run out of air, it’s important to Stop, Think, and finally Act according to the best solution possible, baring in mind that a rapid ascent to the surface may pose a serious risk of Decompression Sickness.
Use The sentence No Air Can Be Bad, and the acronym N.A.C.B.B that will help you remember the order of alternatives you have in an out of air emergency:
Slowly ascend to the surface no faster than 18m/60ft per minute.
. If out of air, your best option is to find your buddy, signal “Im out of air” locate and secure his AAS and ascend with him to the surface.
.If out of air, and can’t reach your buddy, you can inhale deeply and slowly ascend to the surface making a continuous AHHHHH sound, while keeping the regulator in your mouth. As most of us can exhale slowly for more than 25 seconds, you should be able to complete a slow ascent from 20ft/6m without exceeding maximum ascent rate.
4. Buddy Breathing–
a similar option to AAS, where here we use a single regulators for two divers, which requires more coordination and practice. The skill is optional at the Open Water Course.
5. Buoyant Ascent-
Your worth case scenario, should not be practiced fully. Only if you’re:
A. Out of air.
B. Far away from your buddy or cannot find him.
C. in water to deep to perform C.E.S.A
Remember that all the above scenario should be avoided; putting yourself in that position is nearly 100% due to human errors.
At this point all you can do is to remove your weights, and float up. Its important to spread your arms and legs and stay horizontal to slow down ascent rate, and remember to continuously exhale making an AHHHH sound.
Running out of air can lead to serious consequences. Remember, as long as you plan your dive and dive your plans, most dive accidents can be easily avoided.
If you still managed to find yourself in an emergency situation the most important thing is to relax, stop, think and only then act.
Your Open Water scuba skills should prepare you for the worse case scenario; keep your skill level up to date.
If your not to comfortable with your skills- consider a quick refresher course, or upgrade your scuba credentials.