How Dangerous Is Scuba Diving?

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Scuba diving is an exhilarating ocean sport that brings you up close and personal with lush life downunder. It does, however, require plenty of preparing ahead of time because it carries some risks. While the entertainment industry is known to exaggerate the dangers of diving into the deep blue for a grader effect, most recreational dives are a relaxing opportunity to connect to the marine world. However, there are real dangers that exist while diving, and it’s important to be prepared to handle them should they arise. 

If you’re still wondering, ‘how dangerous is scuba diving?’, you’ve come to the right place. Here we’ve gathered the hazards you’ll need to prepare for before your dive, and the proper way to react if you encounter them. 

Potential Hazards

The Bends  

Most non-divers are familiar with the term, “The Bends” from watching TV shows and movies. The technical term is actually Decompression Sickness or DCS. Decompression Sickness is actually a group of maladies that could occur when a diver’s body absorbs too much nitrogen, and then returns to the surface too quickly.  Picture a can or bottle of a carbonated beverage, such as soda. If you shake the container, and then open it, the release of carbon dioxide in the drink will be hastened causing the liquid to overflow. This is similar to what happens with DCS.

When you breathe compressed air underwater, you are actually breathing in more oxygen and nitrogen molecules than you would at the surface breathing regular air. In fact, at 33 feet of depth in sea water, you’re breathing twice as many molecules as you would be at the surface.

The extra nitrogen is absorbed into your blood and tissues. If you ascend too quickly, then the nitrogen can come out of solution causing nitrogen bubbles to form in the body.

Decompression Sickness can affect the limbs, the nervous system, the inner ear, the pulmonary system, and the skin. It is very dangerous and requires medical treatment. Treatment always involves the administration of emergency oxygen and often requires time spent in a hyperbaric chamber.

There are two good reasons why you should not fear getting the bends:

  1. The overwhelming majority of cases of DCS are related to dehydration. A major cause of dehydration is the use of alcohol. If you are going to be diving, you should not drink alcohol for several days before your trip.  You should however, as with preparation for any sport or activity where you will be exerting energy, hydrate several days prior to the activity.
  2. Your training and your dive computer should keep your dive time and depth within safe limits.

That being said, a very small number of cases of DCS go unexplained. But, once again, even in unexplained cases, the problem is often attributed to dehydration.

hyperbaric chamber

Nitrogen Narcosis

Nitrogen Narcosis used to be called “Rapture of the Deep.”  Divers with Nitrogen Narcosis will often find themselves in a stupor. It has been compared to the effects of drinking alcohol. It’s believed that nitrogen, under pressure, can affect the protein coating of nerve endings. 

Nitrogen Narcosis negatively affects a diver’s judgment and spatial  orientation. This makes it hard to keep track of dive time, depth, and amount of remaining air, which are the dangers associated with Nitrogen Narcosis

Luckily, divers do not need medical treatment for Nitrogen Narcosis, itself. They just need to ascend, often just a few feet, in order to relieve the symptoms. For this reason, it is important to always dive with a reliable, trained dive buddy. She or he can often recognize the symptoms, and help their buddy to ascend.

Lung Overexpansion Injury

A lung over expansion injury can occur if you hold your breath during your ascent , while breathing compressed air from a scuba air cylinder. If a person holds their breath, it is possible for the air in their lungs to expand to a point at which the alveoli rupture and the lungs are damaged.  The results can be traumatic and definitely require medical treatment.

This is not a common hazard and usually involves divers error  to incur a lung overexpansion injury. A typical scenario is that a diver panics, rips out their regulator and then bolts to the surface, holding their breath for the duration of the ascent.

Prevention is very easy:

  1. First, if you have to remove your regulator from your mouth, exhale a small stream of bubbles.   
  2. Second, never panic.  The mantra when in trouble underwater is: Stop.  Breathe.  Think. Breathe.  Act. Breathe.
  3. Third, if you find yourself  panicking and bolting for the surface, then leave your regulator in your mouth. It is unlikely  to suffer a lung over expansion injury if your regulator remains in your mouth.
lung overexpansion injury

Running Out of Air

One of the most overused plot devices in scuba-related entertainment is a diver running out of air.  As long as you follow your dive plan, and monitor your time and air consumption, there is little danger you will  run out of air. Even if you think that you are out of air, you likely are not. As you ascend, the compressed air in your hoses will expand, and air in your cylinder will become available. When this occurs, you will get several additional breaths of air.  

In addition, during your scuba training, students are taught two methods for dealing with an out of air situation. These are the emergency swimming ascent, and the buoyant ascent.

Marine Life

First of all, you need to be more aware than to fear  sharks. According to a Stanford University study, a scuba diver’s chances of being attacked by a shark are approximately 1 in 136 million. You would have a better chance of winning the lottery (1 in 14 million) than being attacked by a shark.  In fact, due to the practice of shark finning, and overfishing, many divers may never have the good fortune of seeing a shark. Added to that is the fact that most shark species avoid contact with divers.

If you see a shark in the wild, you should consider yourself fortunate.

A greater hazard is marine envenomation.  The risk of being stung can be mitigated easily.  Wear a wetsuit, and don’t touch anything. When making a dive from shore, shuffle instead of step so that any stingrays will have enough warning to swim away from you.

scuba diver with sharks

The Two Worst Hazards: Boaters and Entanglement

Boaters, and more specifically those who use personal watercraft, are very dangerous to divers.  Always use a surface float with a diver down flag that is at least 21 inches by 21 inches in size.  If you’re operating your own vessel, fly the diver down flag and the International Flag Code Alpha.  In the day time, display the anchor ball, and also the diamond device to show that divers are in the water.  If making a night dive, display a white anchor light and three all-around lights; red over white, over red.

Entanglement refers to getting caught in things such as lines, ropes, nets, or perhaps seaweed or kelp.  Always carry at least one, but preferably two cutting devices, such as line cutters, dive knife, or trauma shears.

Promate KF510-Black, Sharp Tip Stainless Steel Scuba Dive Knife
  • 304 stainless steel blade
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  • Overall Length: 10.5 inch (27 cm), Blade Length: 5 inch (12.5 cm)

Proper Training and Diving Within the Limits of Your Training

When you take your scuba course, your instructor will teach you how to use your dive computer to remain within safe limits for the length of your dive, and your maximum depth. Some instructors also explain the use of the older dive-table method.  As long as you stay within these limits, you should have little to worry about.

scuba divers

Technical Diving and Cave Diving

As for me, I enjoy shallow dives on warm, colorful tropical reefs.  There is much more to be seen near the surface than in the gloomy depths.  Although fascinating, the fish that live at depths beyond the ability of light to penetrate, are far less aesthetically pleasing. 

However, there are divers who like to push themselves. Technical divers use specialized equipment and techniques to dive to depths below 130 feet. Cave divers use similar equipment, but much different techniques to penetrate caves and caverns flooded with water. These types of diving can be very dangerous, even with excellent training and equipment. They should only be attempted by people with a vast number of recreational dives, and the proper training. Moreover, Tech and Cave divers should be highly skilled, well conditioned, specially trained and confident to ensure they are able to manage the challenges presented in this environment.

Divers Alert Network Insurance

Divers Alert Network (DAN) is a diving safety organization that is affiliated with Duke University Medical School. DAN performs four important roles in the diving community: 

  1. First, they conduct research regarding diving medicine and safety. 
  2. Second, they provide medical information to both physicians and the general public with information about diving medicine, free of charge. 
  3. Third, they offer a 24-hour hotline to help divers connect with medical care.
  4. Fourth, they offer a superb level of medical insurance for DAN members, as well as medical evacuation insurance. Depending on the level of your plan, the annual cost of DAN insurance can be less than $100 per year. Whereas, medical treatment for a scuba related injury is rarely, if ever covered by regular health insurance.  

Final Thoughts

Scuba diving is a unique and special experience that should not be avoided because of the risks associated with this water sport. Instead, you simply need to be sure to take your safety into your own hands by getting  high quality training, staying within the limits of that training, and getting dive insurance coverage in case something goes wrong.

Now grab your mask, fins, and snorkel and head on down to your local dive shop to start your dive adventures!

Has this guide helped you to start planning your scuba diving adventure? Or is there something you’d like us to write about next that’s not covered in the Seaside Planet blog? Join the community and share your thoughts in the comment section below!