Scuba Diving Resources
Scuba Diving for Journalists, Writers & Authors: A Complete Reference Guide
What is scuba diving? How to be credible when writing about scuba. Vocabulary. Equipment. Terminology.
Darcy Kieran is the author of the handbook “The Ultimate Beginner’s Guide To Scuba Diving: How to increase safety, save money & have more fun!”
When you write about something you don’t know, you can lose all credibility with just one wrong word. We regularly see this awkward situation happening when authors and journalists write about scuba diving. It may be daunting to research relevant information on such a specialized topic, so here’s a cheat sheet for you.
Take a few seconds to go through some elementary concepts and terminology so that you look smarter the next time you write about scuba diving.
Breathing Air, Oxygen, and Other Gases
Let’s start with the most frequent mistake we read in news articles.
Scuba divers use cylinders (tanks) filled with AIR, not oxygen–just like you breathe air (not oxygen) while reading this article.
Of course, it’s the oxygen in the air that our body needs, but we do not breathe oxygen. Air is a mixture of oxygen (about 21%), nitrogen (about 79%), and traces of other gases.
Here is why it matters so much: Underwater, oxygen becomes toxic at very shallow depths. Even at the surface, you can get oxygen toxicity by breathing supplemental oxygen for too long. And it gets worse underwater because of increased pressure.
There are two kinds of oxygen toxicity. One is related to the depth and one to the length of time.
Central nervous system (CNS) oxygen toxicity can cause seizures, convulsions, and unconsciousness. It is not the end of the world when in a hospital bed. But when you are underwater, seizures and unconsciousness would be very dangerous!
When scuba diving with air with approximately 21% oxygen, CNS oxygen toxicity becomes a severe risk below 60m (200 feet). Recreational scuba divers stay well within safety limits by never diving below 40m (130 feet) and limiting their time underwater.
You can read all about it on Divers Alert Network’s website.
What is Nitrox (Enriched-Air) Diving?
In some cases, scuba divers will use a mix of gases in their cylinder with more than 21% oxygen. This is referred to as “nitrox” or “enriched-air.” The higher the percentage of oxygen, the shallower is the maximum depth at which you can dive. This depth limit is referred to as “maximum operating depth” or MOD.
Other Gases For Scuba Diving
When diving deeper than the recreational diving limit of 40m (130 feet), scuba divers use mixes of gases with less than 21% of oxygen. This is part of what is known as technical diving or “tech diving.” These scuba divers will use mixes of nitrogen, oxygen (like we have in regular air), and helium. When all three gases are present, it is known as a “trimix.”
The Professional Association of Diving Instructors (PADI) & Scuba Certification Agencies
Here is another frequent mistake. Journalists seem to believe quite readily that PADI, the Professional Association of Diving Instructors, speaks on behalf of dive instructors as if it was an association of scuba instructors. But… It is not! Yes, the name is misleading.
PADI is a private company selling training materials to scuba diving instructors who follow standards established by PADI for PADI courses. In the dive industry, we refer to these companies as certification agencies.
Numerous private companies offer this type of service to dive instructors, including SDI, RAID, and SSI. In some cases, these services are provided by not-for-profit organizations like NAUI, BSAC (mainly in the UK), and CMAS (mainly in France).
If they do not speak on behalf of dive instructors, PADI represents even less the dive industry. Numerous dive industry stakeholders are involved in providing scuba diving experiences, like dive gear manufacturers, dive resorts, liveaboards, and local dive centers. What is good for PADI is not necessarily good for the dive industry as a whole, and vice versa.
Licenses & Scuba Diving Certification
In most parts of the world, there are no legal requirements to have taken a course before going scuba diving. It’s the dive industry that self-imposes this requirement. For instance, you could go scuba diving off your yacht even if you are not certified, but you will most likely have to provide proof of certification when you want to jump on a dive charter boat.
Once you have successfully completed a scuba diving course, you become a “certified scuba diver.” It is NOT a license. By definition, a license is a formal permission to do something from a government or other authority. Since there are no legal requirements to get training before going scuba diving, there is no such thing as a license (in most parts of the world). Of course, like with everything else in life, there are exceptions. There are a few places where the government has established regulations for scuba diving, in which cases you may need a permit or other legal documents.
Therefore, scuba divers do not hold a “license”; they merely have a confirmation that they completed a scuba diving course offered by a private company. It’s called a certification card or “c-card.” Nowadays, it is often in an electronic format on a smartphone.
Minimum Age For Scuba Diving
There are two questions here.
How old do you have to be to go scuba diving? The answer is 8 years old. How old do you have to be to get certified as an open water diver? That’s 10 years old. In both cases, these are general age requirements that may be different in certain countries.
In the PADI system of diver education, scuba divers younger than 15 years old (and at least 10 years old) earn a Junior Open Water Diver certification after successfully completing the entry-level scuba diving course.
At 8 and 9 years old, kids can try out scuba diving in the pool with a dive instructor. The programs for kids have different names for different dive training organizations. In the PADI system, they have the Bubblemaker and Seal Team programs.
Of course, there are numerous other considerations besides age when deciding if a child is ready for scuba diving, like their ability to follow the rules. Some may say that scuba diving is a unique family activity where kids can take responsibility while learning more about the planet on which they live.
Inflating, Deflating, Ascending, Descending
A scuba diver inflates the BCD (vest) on the way DOWN and deflates it on the way UP. Yes, it may sound counterintuitive, but when you think about it, it is not.
In scuba diving, we use a vest to control our buoyancy by adding or removing air in it. It is called a BCD or buoyancy control device.
As you go down, there is more pressure on your dive gear and yourself. Therefore the BCD shrinks because the air inside the best is gradually more compressed. For the vest to displace the same amount of water (so that you remain neutral), you need to add air into it.
When you go up, the air inside your BCD expands because there is less pressure around it. The more this air grows, the bigger the vest becomes, and the more buoyant you are. If you do not deflate the vest gradually as you go up, you will shoot up to the surface like a cork, which would be extremely dangerous. It may earn you a trip to a hospital or the morgue.
The Bends, Decompression Sickness, Nitrogen Narcosis, and Other Scuba Diving Decompression Illnesses
There would be a lot to say about scuba diving health emergencies if you wanted to know all about it. We will try to summarize key parts of it for you.
What are the bends? What is decompression sickness?
When you are scuba diving, you breathe compressed air (not oxygen). The concept is simple: Since there is increased pressure around you (caused by the weight of the water), for your lung to inhale the same volume of air as you would at the surface, you need more air because that air is compressed (just like it is inside your vest, as discussed above).
Within the air that we breathe, there is about 21% of oxygen and other pretty useless gases. The main one is nitrogen which is about 79% of what you breathe.
Because you are breathing compressed air, you get more nitrogen in your lungs than you would at the surface. And this gas dissolves inside your body (the explanation of this process would go much beyond the scope of this scuba diving reference guide). When you ascend back to the surface, the nitrogen that was dissolved in your tissues expands.
Scuba divers must ascend very slowly because they need to give a chance for that nitrogen to be evacuated.
In commercial or technical diving, scuba divers may need to do decompression stops at specific depths. This means they stay at a certain depth for a certain amount of time to allow nitrogen to find its way out of their body. In recreational diving, we limit our depth and dive time so that we do not need to do decompression stops. However, we typically perform a safety stop at 5 meters (15 feet) to be on the safe side.
So what are the bends? The bends are consequences of ascending too fast or bypassing decompression stops. That is why the accurate term for the bends is decompression sickness. It occurs when you do not decompress sufficiently underwater.
What is the treatment for the bends/decompression sickness?
As long as no other injuries were created from the nitrogen expanding inside your body, you need to “recompressed” yourself and proceed with extended decompression stops. But you do not go back underwater to dot that; you go in a recompression chamber where a trained operator will monitor you while controlling the simulated depth inside the chamber.
It is often referred to as a decompression chamber, but in reality, it is a recompression chamber followed by gradual, simulated decompression.
Nitrogen Narcosis
Nitrogen again! Another problem that can arise from breathing compressed air is nitrogen narcosis.
What is nitrogen narcosis? Nitrogen narcosis is simply a drowsy state created by breathing compressed air. It is not as bad as the bends, as long as it is a mild case of nitrogen narcosis.
The deeper you go, the more severe nitrogen narcosis becomes. It has been described as a feeling of being drunk. Once you resurface, it automatically goes away. Therefore, the problem with nitrogen narcosis is simply related to the dumb things you may do underwater, similar to what a drunk person can do at a surface. And because you are underwater and dependent on diving gear to stay alive, foolish actions can put your life at risk.
Scuba divers can experience nitrogen narcosis at different depths. It depends on each individual, but it is usually not a significant problem if you stay within the recreational dive limit of 40 meters (130 feet).
SCUBA and Scuba Definition, Acronym, and Meaning
SCUBA is an acronym for Self-Contained Underwater Breathing Apparatus.
It means that you are going underwater with everything you need (self-contained) to breathe underwater instead of diving using air through a hose connected to the surface (used in commercial diving and tankless diving).
Scuba Pronunciation, Scuba Diving, and Diving
Because it is an acronym, in theory, scuba diving should be written “SCUBA diving.” However, nowadays, it is used as a word and pronounced as such. Therefore, we write scuba as a common word, not as an acronym. And we pronounce it “scooba,” not S. C. U. B. A.
Scuba divers will often talk about “diving” without the word scuba, as in “let’s go diving!” This is an acceptable shortening of “scuba diving,” but only when the context makes it clear that we are talking about scuba diving. Otherwise, it would lead to confusion with numerous other types of diving, including the Olympic sport of jumping off a high board.
Scuba Diving Gear
Scuba divers learn about dive equipment and how to use it during their training sessions with a dive instructor. The purpose of this reference guide is not to go as deep into this topic but simply to point out a few mistakes often made by uninformed journalists, authors, and writers.
Scuba Mask and Goggles
Goggles are used by swimmers to keep their eyes dry when their face is underwater. Goggles allow you to see more clearly underwater. You cannot go scuba diving with swim goggles.
Scuba diving masks include the nose in addition to the eyes within the dry compartment in front of your face.
Why is the nose included inside a scuba diving mask? It’s for allowing you to add air to the inside of your mask by exhaling through your nose. You need to do that because the air inside your mask is compressed as you go down (just like we’ve seen in the case of a vest or BCD).
The air you have in your mask at the beginning of a dive (at the surface) gets compressed as you go down. It means that its volume decreases. If you do not add air to maintain the same volume, you will have a mask squeeze (mask or facial barotrauma). Typically, a mask squeeze creates bruising around your eyes, swelling, and blood spots over the white areas of your eyes. It’s not good!
The action of adjusting air pressure inside your mask is referred to as mask equalization.
BCD
A BCD is an inflated vest that scuba divers wear underwater to control their buoyancy. It stands for Buoyancy Control Device.
Sometimes, it is referred to as a BC or Buoyancy Compensator.
A scuba diving BCD cannot be safely used as a replacement to a life jacket carried on boats if a passenger ends up in the water. These life jackets are personal flotation devices (PFDs). They are designed to keep your head out of the water.
We cannot use a scuba diving BCD as a PFD because BCDs are designed to keep you horizontally, face down, which is the preferred way of moving underwater. Therefore, an unconscious person floating at the surface with a scuba diving vest would float with no problem but probably face down, which would lead to drowning.
Flippers and Fins
This is not a significant issue, but so that you know… Scuba divers refer to what they wear on their feet as scuba “fins,” not “flippers.”
Scuba Tanks and Cylinders
This is another minor clarification. When scuba diving, we carry compressed air (not oxygen) in a scuba cylinder, not a “tank.” The word tank is typically defined as the container carrying fuel in a car or a heavy, armored vehicle.
Scuba Diving Jobs
There are numerous kinds of jobs in the scuba diving industry, including accountants and janitors, but the ones we usually think of when talking about scuba diving are divemasters and scuba diving instructors.
Divemasters and dive instructors are dive professional ratings you obtain after completing a divemaster or dive instructor course.
A dive instructor teaches. That’s usually clear!
A divemaster is an assistant to the instructor. We often read articles where the author assumes that the divemaster is above the instructor, perhaps because there is the word “master” in divemaster. But it is the other way around.
Divemaster can also refer to the job of acting as an underwater tour guide for scuba diving tourists. In such a case, a dive instructor may fulfill that divemaster job. In other words, “divemaster” is both a level of dive professional training and a job position that can be done by divemasters or dive instructors.
Swimming Underwater
“The scuba diver was swimming underwater.” There is nothing fundamentally wrong with this sentence. However, it is wrong to systematically associate “swimming underwater” with scuba diving.
Scuba is a set of dive gear used to breathe underwater. Scuba diving is the activity of using that set of equipment to go underwater. I do not need to be swimming around to be scuba diving.
I could jump off a dive boat, go down right there until I am hovering above a coral reef head, stay there to admire the underwater life, then ascend and get back on the dive boat. In such a scenario, I never once swam underwater.
In fact, scuba diving is an excellent activity for paraplegics and even quadriplegics.
Scuba: A Sport or An Activity?
Is scuba diving a sport? No! A sport is usually “an activity involving physical exertion and skill in which an individual or a team competes against another or others for entertainment” (Oxford Dictionary).
When scuba diving, we do not compete, and we try to stay away from physical exertion, which would lead to higher air consumption and a shorter dive time.
Scuba diving is a recreational activity, like birdwatching. Scuba diving is not a sport.
Related But Different Activities: Snorkeling, Skin Diving, Freediving, Tankless Diving
For your reference, here are some water sports and activities that are cousins to scuba diving. Typically, you purchase equipment for these activities at a dive shop.
Snorkeling
Snorkelers use fins, masks, and snorkels, just like a scuba diver does. If you stay at the surface of the water, in theory, you could do snorkeling with swim goggles, but snorkelers tend to use the same type of masks as scuba divers.
Why are swim goggles not recommended for use in snorkeling? Although it is technically possible to use swim goggles for snorkeling if you remain at the surface, a regular scuba diving mask is recommended for snorkeling because it provides you with a better vision, it allows you to clear any water that found its way inside the mask by exhaling through your nose, and the snorkel attaches better to the strap of a scuba mask. And here is the biggest reason: As a snorkeler, you may go underwater, in which case, you would need to equalize your mask just like a scuba diver does.
Freediving
Freediving is a breath-hold diving activity during which you go underwater for an extended period of time and/or to greater depths than a snorkeler would.
Typically, we use the word “freediving” when referring to the sport of the same name as opposed to people doing a bit of freediving recreationally.
We like to write freediving in one word to prevent any confusion with a scuba dive that would be free of charge (free diving).
Skin Diving
In theory, skin diving is somewhere between snorkeling and freediving.
In other words, a skin diver is a snorkeler that swims underwater more than a typical snorkeling tourist does but less than freedivers. It is somewhat of an antiquated term.
Nowadays, we talk about snorkeling or freediving.
Tankless Diving
Tankless diving is also known as surface-supplied air diving. It is like scuba diving but without the “self-contained” part.
Fundamentally, a tankless diving system is an air compressor sitting on a tube and floating at the surface. Long hoses are attached to that compressor. At the other end of the hose, there’s a second-stage regulator (just like what a scuba diver uses), off of which the underwater explorer breathes air. The depth is limited to the length of the hose.
It is often seen as a step between snorkeling and scuba diving or a “snorkeling plus” activity.
Tankless diving systems are sometimes called “hookahs” because they share a familiar look with the instrument used for smoking tobacco, cannabis, and opium.
TL;DR
- SCUBA is the acronym of Self-Contained Underwater Breathing Apparatus.
- We pronounce and write “scuba” as a word, not an acronym.
- Scuba divers breathe air, not oxygen.
- PADI is a private company, not an association speaking on behalf of the dive industry.
- Scuba divers have a certification card (c-card), not a license (in most places in the world).
- You can experience scuba in a pool at 8 years old but need to be at least 10 years old to get certified (in most places in the world).
- A scuba diver inflates its vest on the way down.
- A scuba diver deflates its vest on the way up.
- The bends are a decompression sickness due to improper decompression on the way up after a dive.
- You cannot scuba dive with swim goggles.
- A scuba mask must include the nose in the same air space as the eyes.
- Scuba diving is an activity, not a sport.
- You do not need to be “swimming underwater” to be scuba diving.
Also, from Darcy Kieran:
- Handbook: The Ultimate Beginner’s Guide To Scuba Diving: How to Increase Safety, Save Money & Have More Fun!
- The Best STARTER Scuba Diving Logbook & Checklists while getting your open water diver certification!
- Handbook: Your Career and/or Life as a Scuba Diving Instructor: How to Make a Good Living Out of Your Passion for Scuba Diving!
- The Best ADVANCED Scuba Diving Logbook & Checklists for certified scuba divers, divemasters & dive instructors!
- Reference book: Scuba Diving Industry Market Reports & Statistics.
And if you want to have a taste of scuba diving while you are bored at the office, have a look at my novels with a scuba diving twist, starting with “Mystery of The Blue Dragon” and “Shadows on Ocean Drive.”
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