Scuba diving is a relatively safe activity as long as you follow the rules and necessary safety precautions. However, since we’re not meant to live underwater and need to use a gas tank to help us breathe, emergencies may occasionally arise.
Although scuba diving isn’t a dangerous activity, there are some risks involved. Problems may arise underwater due to faulty equipment or sudden health problems. Let’s take a closer look at the risks and dangers involved while scuba diving:
Even though divers breathe underwater with the help of gas tanks, drowning is a potential risk, despite having plenty of oxygen left in the tank. A sudden panic attack or losing consciousness underwater are common causes of drowning while scuba diving. These problems may be the result of faulty equipment (such as a malfunctioning regulator) or any medical condition the diver may have.
This is why all dive agencies conduct a health test to screen divers before they’re ready to get in the water. Having a dive buddy or trainer with you also helps in case you have a panic attack or a problem with your equipment. They can help you get back to the surface in time. Make sure all your gear is intact before your dive. If something seems out of order, get it repaired or replace it before getting in the water.
This is probably the most well-known risk associated with scuba diving. Since you breathe in compressed air when you’re underwater, absorbing too much of the compressed nitrogen can cause the build-up of gas bubbles in the body. This usually happens if you ascend too fast.
These bubbles cause joint pains, tissue damage and are overall quite unpleasant. It is important to keep an eye on your dive computer (or tables) and make decompression stops where required for the right amount of time. Avoid diving to lower depths if you are not physically fit enough or don’t have the necessary certification.
In order to dive to a depth of 25 meters or deeper, you need special training. This is because as the depth increases, so does the water pressure and the amount of compressed nitrogen entering your body. Too much nitrogen can have a laxative effect on the body and can slow down your senses and physical movement. This can potentially lead to decompression sickness, or in the worst case, drowning.
While most marine creatures don’t harm divers, they may suddenly become aggravated and attack. Getting stung by stingray or jellyfish is also possible. It is important to not do anything to disturb the animals or corals underwater, both to stay safe and to avoid causing them any damage.
Here are some common emergencies that any diver may face mid-dive:
If you’re diving in very cold water, the sudden impact on your skin can cause you to hyperventilate and potentially drown.
Although divers wear dry suits, etc., to stay warm underwater, heat loss from the body is still possible, especially if you dive more than once a day. It may also lead to “immersion diuresis”, a condition that causes dehydration, syncope and arrhythmias.
Barotrauma is characterized by pain in the ears and sinuses, caused by the compression of the scuba mask against the face due to water pressure.
Divers are trained to equalize pressure in their ears when they’re underwater. This is because an imbalance in pressure can damage the ear drum and cause pain and internal bleeding. Water entering the ears may also cause vertigo.
Ear damage can occur both during ascent and descent and if it becomes very severe, it may lead to permanent loss of hearing. If you suspect that you have barotrauma, do not enter the water until your physician has given you the green signal.
If a diver holds their breath during ascent, the air expands inside the body and can cause severe internal damage, such as rupturing a lung. Arterial Gas Embolism (AGE) may occur if these gas bubbles are forced into the bloodstream. Sometimes, the symptoms of AGE are noticed a few minutes after the dive. These include chest pains, suffocations, dizziness, foaming at the mouth (or blood) numbness, paralysis, etc.
Although scuba diving doesn’t directly cause any problems, such as joint pains or breathing difficulties, medical problems may still arise. These include:
The most dangerous problems due to scuba diving include lung barotrauma and decompression sickness.
Barotrauma occurs when gases expand inside your lungs as you ascend. For some divers, this can even cause a lung to collapse. Some gas bubbles may also enter the bloodstream and cause chest pains, breathing difficulties and severe problems, such as a stroke.
We’ve already covered how decompression sickness occurs and what its common causes are. Apart from joint pains, decompression sickness may also lead to more serious problems, such as damage to the spinal cord, brain and lungs.
Certain emergencies, such as nitrogen narcosis, barotrauma and faulty equipment, can hinder your breathing underwater. If you are unable to reach the surface quickly, death is a possibility.
In order to avoid such dire situations, it is essential for divers to be in good health, have properly functioning gear and a diving partner when they get in the water.
A dive mask is an essential component of any scuba diver’s gear. Apart from keeping the diver from inhaling salty water, it also allows them to clearly focus on the water and everything in it. Every now and then, new types of dive masks are manufactured to help the diver see better and feel more comfortable in the water.
Which brings us to the question: would polarized dive masks increase clarity of vision underwater?
Before we look into what a polarized dive mask is, let’s start off with what the purpose of a polarized lens even is:
Polarized lenses work by reducing the glare of the sun (which causes light to reflect off surfaces, such as cars or the water). Glare can reduce a person’s visibility, so many people opt for polarized sunglasses, especially when driving to avoid this problem.
In fact, many people use polarized lenses when fishing to be able to see under the water surface.
Since a polarized mask reduces glare and allows those who are fishing, etc., to be able to see underwater, it seems only fitting that a polarized dive mask improves a diver’s vision underwater. But how exactly does a polarized dive mask work?
Research indicates that water molecules are formed in such a way that the light that enters the water is already partially polarized. A polarized mark further helps divers see better underwater.
In fact, “anti-glare” masks have started gaining some popularity among divers nowadays. These masks not only make everything appear to be brighter and more vibrant underwater, they also increase the range of a diver’s vision. On average, around 10% of light is reflected (aka lost) by regular dive masks. Anti-glare masks have properties that increase light transmission to around 98%. They reduce the strain on the diver’s eyes, which becomes a great advantage for frequent and professional divers.
Polarized dive masks may add around USD 50 or more to the standard cost of a scuba mask, but is it worth the additional expense? Many divers feel that the protective coating on polarized masks is a gimmick, which just makes the lens a little tinted without doing anything to reduce glare.
However, getting a polarized mask from a well-reputed brand and one that has received positive reviews from other divers is a good idea. Such masks are likely to be helpful, particularly for specific types of dives:
In certain conditions, a polarized mask becomes necessary. This includes night-time dives, diving in water with lower visibility than normal and also for underwater photographers who need to capture the right shot.
Although some divers are suspicious of polarized dive masks, polarized snorkel masks have considerably greater benefits. Snorkelers may go a few feet into the water, but they generally return to the surface within a few moments and observe life under the ocean at the surface. Beginners may be hesitant to completely submerge themselves in the water and may only look into the water facedown.
Polarized masks reduce glare and allow snorkelers to see deeper into the water with more clarity. Snorkelers may be able to observe more sea creatures and corals without having to deal with the light reflecting off the surface of the water, making the entire experience more enjoyable for them.
Since water is already partially polarized, science indicates that tilting your head sideways in the water would greatly obstruct your vision. This is because the lens will polarize light entering the water vertically, which means a diver may be exposed to pitch darkness if they turn their head the wrong way.
For this reason, polarized dive masks have not really gained much popularity and are rarely talked about by professional divers and dive instructors. While they offer certain benefits (such as a clearer view and a greater scope of vision) for snorkelers, they don’t offer anything much of value underwater.
Polarized masks do not have magical anti-fog properties and need to be de-fogged before your dive to avoid issues later on. Just follow the same method you would use for a regular dive mask (such as using toothpaste), but you’ll have to be a bit more careful to avoid scraping the coating.
Although it’s unlikely that you’ll find renowned brands supplying polarized dive masks, you can buy polarizing sheets and insert them on top of the lens in your dive mask. Polarized dive filter lenses can also be bought online and from a select few dive stores.
One important factor to remember with this additional coating is that the mask becomes more prone to damage. The coating may easily get scratched during your dive (or snorkel) or as you clean your mask if you’re not careful enough. Over time, the coating may start peeling on its own. This coating may also leave minor scratches on the actual lens of your mask.
Research is being conducted on introducing polarizing properties to underwater cameras to get clearer, sharper images underwater. The concept of attaching a polarizer to the camera has also surfaced and some research has been conducted on it, but nothing concrete has come of it as yet. However, such ideas are still in the testing phase and divers are still able to capture amazing views of the ocean with their standard underwater cameras.
It appears that there’s a very good reason why companies haven’t jumped onboard the trend of polarized dive masks – their benefits are minimal. While polarized snorkel masks may still serve a purpose, the polarizing properties of the lens become nearly redundant underwater. The additional expense and sensitivity of the polarized mask make it more of a liability than an asset.
Scuba divers are better off with standard dive masks. As long as the proper maintenance measures are taken and the mask doesn’t fog up underwater, you’ll be able to see clearly under the water and make the most of your dive.
Scuba diving is a hobby and sport that is continuing to increase in popularity every year. When learning to scuba dive, multiple factors need to be taken into consideration – finding the appropriate diving equipment, searching for the perfect location, learning the right diving qualifications, etc. All of these factors are essential. For scuba divers, the risk of decompression sickness plays an important role; therefore, it’s always best practice to gain complete knowledge about this activity before indulging in it.
Decompression sickness (DCS), also known as the bends, diver’s disease, caisson disease, and aerobullosis. It is a condition that arises during depressurization from dissolved gases that come out of the solutions present in your body in the form of bubbles.
While underwater diving decompression is the main cause of this disease, other depressurization events such as extracurricular projects from spacecraft, flying in unpressurized aircraft at high altitude, and emerging from caisson can also cause you to experience DCS. Here is all you need to know about the bends in scuba diving:
As mentioned above, the bends occur in scuba divers, high-altitude flyers, and during aerospace events, when dissolved gases (mostly nitrogen) come out of solution in bubbles. This disease can affect any body part including the skin, heart, brain, lungs, and joints.
Scuba divers, astronauts, and aviators experience rapid changes in pressure during scuba diving and from sea level respectively. Commercial divers breathe a special mixture of helium and oxygen known as heliox. In all these situations, bubbles of gas are formed inside the body and cause the bends. We’ll focus on the bends in scuba diving in this article, as it is known as the most common activity resulting in the mentioned disease.
As a scuba diver descends into the water, the pressure of nitrogen or any gas from their air tank increases. The nitrogen causes the pressure to go up an additional 11.6 pounds per square inch for every 33 feet of depth in ocean water.
Unlike the oxygen present in the diver’s tank that gets utilized by them while swimming underwater, the body doesn’t make use of the nitrogen gas; therefore, with the increase in pressure due to nitrogen, more of this gas gets dissolved and builds-up over time into the diver’s body tissues. The longer they remain at depth, the greater the amount of nitrogen that gets dissolved.
A diver’s blood flow gets blocked, and their nerves and blood vessels are disrupted when they return to sea level and nitrogen bubbles are released. This causes stretching and tearing of the blood vessels and nerves. Some of the other problems caused by this are emboli, blood coagulation, and the release of vasoactive compounds.
To understand the bubble formation process further, a can of carbonated soda can be used as an example. The soda can is filled with carbon dioxide gas which is not visible; it is completely dissolved under pressure until the can is opened.
As soon as you open the can, the pressure gets released which causes the gas to escape from the solution in the form of bubbles. Similarly, a diver’s return to the surface is quite similar to the opening of the can of soda.
As a scuba diver swims to the surface of the water, there is a significant decrease in pressure. The nitrogen that has already dissolved in the diver’s tissue seeks to leave again, as the human body is only capable of holding a certain amount of gas, depending on that nitrogen pressure.
You can take some preventive measures for the bends or decompression sickness by carefully listening to and understanding the guidelines taught during professional diving courses and strictly implementing those guidelines while diving. You should also be aware of the actions that play a huge role in increasing the risk of developing the bends. Following are some important factors to consider to minimize the risk of developing the bends.
Never dive outside dive table recommendations. Proven to be a great resource for scuba divers, dive tables are charts that usually come in booklets or printed on cards that help divers in determining various aspects of specific dives, relating to breathing gas, and when to take decompression stops during those dives.
Due to the rapid advancements made in technology, we now have the dive computer, also known as a personal decompression computer or decompression meter. This is a great device that can be used in place of those tables. It is used by an underwater diver to measure the depth and time of a dive so that a safe ascent profile can be calculated and displayed to help the diver avoid DCS.
It is recommended to fly 12 hours after your last dive, given that you dove within the dive tables and didn’t require any decompression stop
If you were involved in complicated diving, it is recommended to wait for 48 hours before you fly
In general, the longer you wait to fly after scuba diving, the less your chances of developing the bends will be. However, even long waits do not ensure 100% immunity to the disease
Divers Alert Network (DAN) collected some data from 1987 to 1999, showing that 17% of scuba divers in their injury database experienced their first symptoms of decompression sickness either after or during flying.
Temperature also plays a vital role here. Diving in cold water is highly discouraged. The volume of the gas shrinks when exposed to low temperatures; this increases the chance of the bends developing.
Obesity can affect lipid metabolism. Obese individuals have a higher chance of developing the bends as nitrogen is lipid-soluble
According to a study on the effects of dehydration on the risk of severe DCS, it was concluded that dehydration significantly increases the overall risk of severe bends disease.
The blood flow of the body increases and so does its ability to carry gas when you expose it to intense exercise and exertion during diving. When you go in extreme depths during a dive, remember to keep exertion to a minimum.
Take the following steps to recover from the bends:
If you notice any symptoms or signs of the bends within 48 hours of diving, you should seek immediate medical attention. Along with informing your doctor of your symptoms, also mention your recent diving activities in details for them to get a better understating of your condition.
Following are some risk factors that increase the chances of decompression sickness:
Poor physical health and medical fitness can increase the risk of the bends for a diver. Regular strength training and aerobics are recommended to maintain or improve physical fitness.
As the atmospheric pressure on the ground is higher than the pressure in an aircraft cabin, flying after scuba diving can increase decompression stress and also the risks of a diver developing the bends.
Extreme exertion right after a dive increases your blood flow along with the capacity of your blood to carry gas. Therefore it is best to avoid any intense exercises right after your dive.
Moderation is the key here. It is best practice to avoid long exposures to cold water without wearing protective suits that come with active heating. Taking hot baths right after cold-water dives can also provoke DCS.
A scuba diver can, in fact, die from the bends. There are various symptoms of the bends which mostly include pain in the joints, arms, and legs. If one suffers from more severe symptoms such as difficulty in speaking or walking and dizziness, they can be signs of serious cases of the bends and can lead to a coma or death.
Although not life-threatening, type 1 DCS can be a warning for type 2 DCS development.
Bubbles form in skin capillaries and result in a rash, often near the shoulders and the chest.
Joints ache and/or pain. The pain either remains in one place or moves around the joint.
These syndromes can be life-threatening and usually affect the nervous system.
Bubbles affect the nervous system and symptoms include respiratory problems, numbness, unconsciousness, and tingling. This decompression syndrome can lead to paralysis or even death if left untreated.
Bubbles form in lung capillaries. This syndrome can interrupt blood flow to the lungs and cause life-threatening heart and respiratory problems.
The bubbles find their way into the arterial bloodstream, transfer to the brain, and lead to an arterial gas embolism. The symptoms include headaches, unconsciousness, confusion, and blurred vision.
In scuba diving, one breathes underwater and explores a whole new world. Discovering its thrills can be a life-changing experience for some. Its history goes way back, centuries back in fact.
In ancient times, simple resources that were used for breathing underwater were neither very safe nor extremely effective. In reality, it took decades before the modern scuba techniques were developed.
Here is a brief look at some important highlights in the history of scuba:
Yes, scuba diving was present in ancient times. As we all know, scuba diving today is largely attributed to Jacques-Yves Cousteau and Emile Gagnan but its history goes back to the Greeks and Aristotle.
Aristotle wrote in his work that Greek sponge divers made use of a bell filled with air that was lowered down to them to the bottom of the Mediterranean when they picked sponges off of there. However, the air limitations restricted their movement and the amount of time they could stay underwater. During a few dives in 332 BCE, Alexander the Great has also been known to use a crude diving bell.
In 1772, Sieur Freminet developed self-contained air equipment for the first time which somewhat resembles today’s scuba set. The air inside the diving bell could be recycled through his scuba apparatus. However, after spending only 20 minutes underwater in his new invention, Freminet passed away because of lack of oxygen.
A different type of self-contained air device was then developed by William James in 1852. The device contained an iron belt that was attached to a copper helmet. This apparatus held air that was sufficient to accomplish a dive of a total of 7 minutes.
Around a century later, in 1939, Christian Lambertsen also developed a self-contained underwater oxygen-breathing apparatus. His invention was specially made for the U.S. military. Although his device was a success in shallow waters, the high levels of oxygen toxicity that were created by it made the apparatus unsafe to be used in deep bodies of water.
All of the above inventions bring us to Cousteau’s and Gagnan’s contributions to the scuba world. Modern scuba diving was co-invented by the two brilliant Frenchmen and their invention opened doors for anyone interested in diving underwater. Jacques-Yves Cousteau concluded that for self-contained breathing apparatuses, compressed air that was further purified and filtered was the optimum gas mixture.
During World War II (between 1942 and 1943), Jacques-Yves Cousteau and Emile Gagnan made alterations to a pressure regulator created by Gagnan originally to overcome the shortage of resources, such as petroleum, caused during the war and allow transport vehicles to run on vegetable oil. After the necessary adjustments, Gagnan’s regulator was capable of sending air at the required pressure. The pair then formulated the Aqua-Lung apparatus which was the main stepping stone for the creation of today’s scuba diving gear. The creation of Aqua-Lung will be discussed in detail later in this blog post.
Regulators have been a part of scuba diving since ages. In a diving regulator, a demand valve is a mechanism which is used to control a gas supply to provide the air flow when the user inhales and the supply is shut off when the inhalation stops. In 1838, the first recorded demand valve was invented in France which was soon forgotten.
A French mining engineer Benoît Rouquayrol developed a demand valve with an iron air reservoir in 1860. The purpose of this device was to allow miners to breathe in flooded mines. He named his invention régulateur.
In 1864, Rouquayrol worked together with Auguste Denayrouze to adapt the regulator to diving. The invention was then mass-produced but the French divers never accepted it entirely due to lack of autonomy and safety.
Yves Le Prieur and Maurice Fernez patented a constant flow regulator together in 1926. This device was hand-controlled and wasn’t a demand valve. It contained a full-face mask and the air escaped at a constant flow from the mask.
Georges Commeinhes, a French inventor, patented a demand valve in which the air supply came from 2 gas cylinders using a full-face mask. The invention was an adaptation of the previous mechanism of Rouquayrol and Denayrouze. However, it was soon forgotten after Commeinhes’ death in 1944.
The demand valve that gained the most widespread acceptance was the one mentioned earlier in this blog post by Cousteau and Gagnan. Gagnan adapted the Rouquayrol-Denayrouze regulator and made it compact. Cousteau suggested that it should be used for its original diving purpose.
Ted Eldred from Australia invented a single hose regulator in the early 1950s. The device used a mouth-held demand valve and intermediate pressure gas was supplied from the cylinder valve. E. R. Cross invented a device called the Sport Diver in 1951. It was one of the first single-hose regulators made in America. This version was based on the oxygen system adapted by pilots.
In 1950, other early single-hose regulators developed, including Sportsways’ Waterlung, Rose Aviation’s Little Rose Pro, and the Nemrok Snark.
In 1955, Bronnec and Gauthier took out a patent in France for a single hose regulator later given the name “Cristal Explorer”. In the tradition of the Rouquayrol-Denayrouze mechanism, the single hose regulator was later adapted for surface-supplied diving. Full-face masks and lightweight helmets were used for the purpose.
The KMB-8 Bandmask was developed by Kirby Morgan in 1969 using a single hose regulator. By 1976, this was further advanced into the Kirby-Morgan SuperLite-17B. Finally, in 1994, Kirby Morgan and Divex worked together and developed a reclaim system to retrieve costly helium mixes during deep-water operations.
Determining who the first person to scuba dive is a difficult task. According to several diving historians, William James, an Englishman invented the first open-circuit scuba system in 1825 and he is the first individual to use a device that vented the air you take into the water as opposed to the divers using “re-breathing” devices. Although it is also believed that while the device was patented, it wasn’t ever used in the water.
Others say Alexander Lambert is the first scuba diver, as he was the individual who first successfully used Henry Fleuss’ re-breather in 1880. The device was used by Lambert for an underwater construction project and allowed a diver to remain submerged for up to three hours.
If you go back even further, Doctor Freminet invented the first self-contained diving system in 1771. He named it the Machine Hydrostatergatique. Freminet dived successfully for a few minutes at a time at a depth of about fifty feet with a copper helmet and a copper air tank. However, most scuba enthusiasts refuse to consider him as the first scuba diver according to the modern system and definition of scuba.
Some diving historians might disregard all the above statements and claim that while their roles in making modern scuba diving a reality are extremely valuable. However, they don’t qualify. Their argument is that Jacques Cousteau and Emile Gagnan were the first true scuba divers. They invented and perfected the Aqua-Lung, which is the exact system that modern divers use today.
Even though determining exactly who the very first person to scuba dive is next to impossible, each of the inventors mentioned above developed key innovations and provided stepping stones for modern scuba diving.
In 1943, the Aqua-Lung was invented in Paris, France by French Navy Lieutenant Jacques Cousteau and an engineer Emile Gagnan. Cousteau’s father worked in Paris for a company that specialized in compressed gases. He was introduced to Gagnan by his father who had been working on valve designs. Together, they made adjustments in a regulator invented by Gagnan and named their new device the Aqua-Lung.
While conducting tests to verify the working of their invention, they discovered the threats of deep-sea diving. While going too deep in the water could cause nitrogen narcosis leading to crazy behavior, coming up to the surface too fast could result is the bends and intense symptoms such as severe pain, dizziness, etc. from the nitrogen bubbles expanding in the blood.
Cousteau spent his entire life exploring the sea. The modern name for Aqua-Lung is SCUBA, meaning Self-Contained Underwater Breathing Apparatus. It makes it possible for divers to go far below the surface of deep-water bodies and allows them to stay there for a prolonged period to explore caves and shipwrecks, study sea life, construct underwater equipment, and more.
A dive regulator makes it possible for scuba divers to breathe underwater. It delivers air from your scuba tank to you in such a way that after a few dives, breathing underwater starts feeling almost as natural as breathing on land.
No matter what sort of a dive regulator you have, they will all have these basic features:
Before we look at the differences between a balanced and unbalanced regulator is, let’s look at what each of them actually is:
Basically, a balanced regulator allows the diver to put in consistent breathing effort, regardless of a change in tank pressure. In other words, the first and second stages of the tank are always balanced.
With an unbalanced regulator, you will have to put in more effort to breathe as the pressure in the air tank decreases.
Now that we’ve covered the basics of what exactly balanced and unbalanced regulators are and what benefits each of them offers, let’s just summarize the core differences between the two:
The first stage for the diaphragm and piston of the regulator involves balancing air pressure so that it does not impact the force required to keep the valve of the first stage shut. This amount of force determines something known as Intermediate Pressure (IP).
In unbalanced regulators, in the first stage, the air from the tank exerts a greater force on the valve to keep it shut. As the air pressure in the tank reduces, this force on the valve is reduced.
It is important to remember that in the first stage, the air pressure in the second chamber is meant to build up until it reaches the IP and automatically shuts the valve to cut off air coming from the tank. In essence, the lower the force to close the valve, the lower the required IP, which is definitely a bonus in balanced regulators.
The diaphragm first stage is balanced for both types of regulators.
Second stages have a spring-operated valve that stays shut until a diver needs to inhale. IP from the first stage pushes against the spring to open the valve. In balanced regulators, the second stage makes use of a little bit of IP air to “fight against” the pressure of the first stage.
In a balanced second stage, the spring to keep the valve closed is much lighter because the IP is helping to keep it shut. As the air pressure decreases, the force fighting against the valve also decreases so the overall pressure on the valve remains unchanged, even if the tank is nearly empty.
Unbalanced second stages have a much heavier spring, so as the IP decreases, it is harder for the valve to open and you must exert more physical effort to breathe.
As we discussed before, balanced regulators are pricier, but they offer the benefit of being able to breathe comfortably, which is why they are the preferred choice for professional divers.
Although both balanced and unbalanced regulators can be used for deep dives, balanced regulators have the advantage of making it easier for you to breathe, regardless of how close you are to finishing your air supply.
They are ideal for professional divers such as those who wish to record their dive, go cave-diving or explore shipwrecks since they need to conserve as much energy as possible.
Although balanced regulators have a number of benefits, the unbalanced ones can be quite useful for recreational diving. This is because there is something known as having an “overbalanced” regulator. In these regulators, the IP increases with increasing depth and has little to no impact on the actual performance of the regulator.
In such cases, it is better to opt for unbalanced regulators, which are not only lighter on the pocket, but they’re also great for divers since it is quite obvious when the air supply is diminishing.
A question that is sometimes raised is why are all regulators not balanced? One factor is the cost involved. The structure of the balanced regulator is more complex and a little more delicate than that of the unbalanced regulator, which raises the price.
Another factor is that a balanced regulator is not always the best choice for a dive. For beginners and shallow divers, unbalanced regulators are actually easier to use.
Some divers use a mix of both: a balanced first stage combined with an unbalanced second stage, provides the best of both worlds. Not only is it pocket-friendly, it also helps divers know when they’re running out of air.
The overall difference in the performance of both regulators is very minor, and most frequently divers make their decision based on their budget.
Having the right scuba gear is essential for divers. But to make sure your gear lasts long, keeping it in good shape is important. One necessary component of your scuba gear is the dive mask. This not only protects your eyes, but it also helps you see clearly underwater.
It is crucial to follow the proper maintenance measures to ensure that you clean your dive mask without getting any scratches on the lens and without stretching out or tearing the silicone.
The skirt, straps and bands of the dive mask are usually made of silicone (there are also rubber mask options available). The lens may be made of either glass or plastic. Different parts of the mask can be cleaned using different methods. However, if any part of the mask is destroyed, you will need to replace the entire mask.
The basic purpose of the skirt is to act like a second skin and help the mask seal on to your face so that water can’t get in. Although expensive, silicone masks are comfortable on the face (as opposed to the plastic ones) and hence, are a preferred choice for most divers.
Clear mask skirts give divers better peripheral vision underwater, which can be particularly useful if you’re diving in murky, cloudy waters. Since they allow more light to enter, they also feel more open and comfortable to wear.
Opaque masks prevent your eyes from being affected by the sun’s glare and are ideal for underwater photographers. However, the dark frame can feel a bit claustrophobic at times, especially if you’re diving at night.
Constant and frequent exposure of silicone to sunlight and humidity can cause it to harden, discolor and lose its shape so that the mask won’t seal properly.
Fortunately, there are a few ways you can revive discolored silicone and prevent it from attaining further damage.
Exposure to water and humidity over the years can cause clear silicone to turn yellow. In some cases, this yellowing can be cleaned off using basic cleaning items that you probably already have at home. If the discoloration is very severe, it may also be a sign that your mask is too old and needs to be replaced. This is because over the years, the silicone stretches out and may not be able to seal properly on your face.
If you are planning to fix your yellowing mask, here is what you can do:
Bleach can be used to clean the silicone, but make sure that the lens is properly covered as you work so that it doesn’t get damaged. Also, make sure that you dilute the bleach with water since concentrated bleach can damage your mask. Avoid using chlorine bleach on your mask since it can cause discoloration and the silicone to harden.
Start off by scrubbing the silicone with some soapy water and drying it off. Next, fill a spray bottle with bleach and spray the silicone of the dive/snorkel mask. Let it sit for around 15-20 minutes. This will kill the mold and clear the yellow color.
Wear rubber gloves the entire time you’re working with bleach. Rinse the mask with cold water and wipe it with a soft cloth to get rid of any residue.
If your mask has been sitting inside a cardboard box at the back of your closet, you’ll need to get it serviced by your local dive shop before it can be used again. Especially, if it’s been there since forever, you’ll need to get it serviced so that it seals properly and doesn’t fog up when you finally get into the water.
Apart from defogging your lens, the abrasive agents in the toothpaste can also help remove the yellowing from a clear silicone mask. Rub the toothpaste on the silicone, let it sit for around 15 minutes and rinse it off. Clean the mask with a soft cloth to get rid of any residue.
This method may not be 100% effective if the mask is very old.
Keep your mask in an airtight space, away from any rubber items (since they can cause color bleeding) and liquid items, such as moisturizer, suntan lotion, and so on.
A black silicone mask doesn’t discolor or soak up color from rubber/neoprene items. They also experience less glare from the sun.
You will still, however, need to service the mask. Even if the silicone doesn’t discolor, it can still get damaged and brittle.
Black mold can start creeping in on the edges of your mask. Mouthwash can be used to kill the mold, but make sure you don’t leave it on for too long and that you rinse and clean it off properly. The chemicals in mouthwash can be corrosive and can eat away at the silicone if it’s left on for too long.
If you’re using a black mask, you’ll have to be extra careful since the mold won’t be visible on the black surface. As long as you service your mask properly and regularly, you shouldn’t have a problem.
Apart from the skirt, straps and bands, the lens of the mask also needs to be cleaned and defogged regularly.
Common household items, such as toothpaste can be used to clean your dive mask. The abrasive texture of the toothpaste makes it great for defogging your mask. It is recommended that you use regular white toothpaste instead of the gel paste.
Toothpaste can only be used on masks with a glass lens. Dive masks with a plastic lens can get scratched easily if you use any kind of abrasive material on them, and they usually have an anti-fog layer already in place.
Simply take a pea-sized amount of toothpaste and rub it on both sides of the lens (the mask should be completely dry when you do this). Rub it in with your fingers in a circular motion.
Rinse the lens and rub at the toothpaste simultaneously. You may need to use a small washcloth to get into the tighter, cramped spaces. Once all the toothpaste is gone, dry the lens completely.
These steps have to be repeated 5-7 times to completely defog your lens. Once you’re done, dry your mask completely before storing it/using it. This defogging process needs to be performed regularly after a few dives.
It is recommended to avoid using toothpaste with any prominent flavor, such as mint that can potentially make your eyes sting a little. However, as long as you’ve been thorough in getting all the toothpaste out, you should be fine.
Items such as baby shampoo can be used as an alternative to toothpaste. Perform the same steps that you would follow if you were using toothpaste and it’ll get the job done.
Apart from properly cleaning and defogging your mask, you also need to be careful when handling it to ensure that the surface doesn’t get scratched and damaged.
Never place your mask lens-side down on the sand or your dive boat. Sand, dirt and grit can permanently damage the lens, making it difficult for you to see underwater. After your dive, rinse your mask, dry it with a microfiber cloth and store it in your dive bag to keep it out of harm’s way.
Salt and grit can ruin the silicone of your mask. If you’re performing multiple dives per day, instead of rinsing your mask, just douse it with a bucket of fresh water to remove any grit and dirt particles between dives.
Prolonged exposure to sunlight causes malleable, transparent silicone to turn yellow, hard and degrade significantly over time. Mask bands and straps may become brittle and snap. Store your mask in a well-sealed container, away from sunlight. It is also advisable to keep a silica gel packet in the container to keep any excess moisture out.
Although it might seem a bit odd to keep moisture at bay when masks are meant to be worn underwater, it is the constant and prolonged exposure to humidity that can damage the mask.
Although dive masks are often one of the less expensive items in your scuba kit, they’re also one of those items that need to fit perfectly. Even if you’re traveling and renting your scuba equipment, you’re likely to keep your own dive mask. This is why it is essential to keep your silicone dive mask clean.
Scuba gear such as a tank, dive suit and dive computer is essential when you’re going for a dive. But the question remains, is a snorkel required for scuba diving?
Snorkels are definitely not needed for technical and commercial diving, but there is some debate about their use during recreational diving. Let’s go into a bit more detail and see why some divers believe that snorkels should be a part of their scuba gear while others are completely against the idea.
What exactly are the benefits of using a snorkel during your dive? You already have your scuba mask and tank to be able to breathe underwater, but there can be some advantages of having a snorkel with you.
A snorkel helps you conserve air in your tank when you’re swimming on the surface before or after your dive. As you swim, you can also see where you’re headed underwater without having to constantly come up to breathe. It is especially useful if you’re swimming for a long distance before you begin your descent.
Although the air supply you’ll use up from your tank on the surface is usually minimal, it can be quite significant if there’s a high tide and the waters are rough. In such situations, your snorkel really comes in handy.
A snorkel isn’t always useful at the surface. For a short swim, a snorkel actually increases your carbon dioxide intake and it’s better to just swim without one. Similarly, if the waves are rough, it is better to descend earlier than planned since this will actually help you conserve energy.
If you’re waiting for your boat and breathing your snorkel, the unwelcome smoke from the boat will start seeping in through your snorkel. The dive regulator helps you avoid this problem. The wait is generally not significant, but if you’re with a large group of people, you may be exposed to the boat’s fumes for quite some time.
If you’re swimming from the shore to your dive point and not going by boat, a snorkel can be particularly useful. You’ll have to swim a significant distance before you’re ready to begin you descent which means you’ll save a considerable amount of air in your tank
As you swim to your dive point, you can put your head in the water (without having to come up constantly to breathe) and gauge where you are, where the corals appear to be the thickest and brightest and choose where to descend accordingly.
You cannot rely on your snorkel to breathe underwater, but if you do make an emergency ascent and your tank has run out of air, you can rely on the snorkel to help you breathe as you swim back to your boat or to the shore. The snorkel will help you calm down and regulate your breathing at the surface.
Although snorkels help you conserve air at the surface, there are a number of reasons why divers avoid carrying one on their dive.
Strong water currents will tug at the mask which will in turn pull at your scuba mask strap. This can either cause minor leaks in your mask or flood it entirely. Even if the mask doesn’t move, the snorkel will keep moving around and bumping everywhere which can be quite annoying.
It is important to note that this may not the case with every snorkel design. Some snorkels have a sleek design that doesn’t move around much in the water. Even slightly tilting your head to the side can reduce the drag caused by the snorkel.
In some cases, snorkels can be more of a nuisance and their benefits may be greatly outweighed by their cons. It is easy for beginners to mistake the snorkel for their dive regulator and breathe through the wrong piece when they initially get in the water. Being hit by a salty wave underwater can not only be annoying, it can also be dangerous if the diver chokes in the water and is unable to breathe. However, this is a rare occurrence and divers generally don’t make such a mistake.
Having a foot-long piece of plastic attached to the side of your mask is an open invitation for it to get stuck anywhere. Your snorkel can get stuck in a reel line or the hose of your BCD. In fact, dive instructors advise students to not wear a snorkel if they’re going cave diving or exploring shipwrecks underwater.
Although there are many components of a scuba divers gear such as their hose, fins or tank valve that can come in the way or get stuck, the aim is to minimize the number of loose items when you’re underwater. If you’re a professional diver who has been diving for a long time and is extremely comfortable in the water, a snorkel won’t bother you.
Even just having the snorkel dangling on the side of your face can slightly obstruct your vision and distract you during your dive. It can flop around as you’re trying to adjust your gear and might even get tangled up with your equipment.
These problems however, are generally experienced by newbies and expert divers are unlikely to face them.
Taking a snorkel on your dive seems like a double-edged sword at times- you like conserving your air supply as you swim to your desired dive point, but once you’re in the water, the snorkel constantly comes in the way. It appears someone figured a way out with the folding snorkel. It provides all the basic functions of the snorkel, but can be folded so it’s compact enough to carry around freely.
One solution to the problems presented by the use of snorkel during your scuba dive is the use of a folding snorkel. The folding snorkel (also known as a collapsible snorkel) can be folded up and stored inside your BCD pocket or attached to your BC. If you need to use it, you can just detach it, unfold it and attach it to your mask.
This way, the snorkel won’t be a bother while you’re underwater, but you’ll still be able to use it to breathe at the surface and swim back to your boat.
However, there is something to look out for with these collapsible snorkels. The flexible design makes them so soft, that they may waver in the breeze and require you to inhale sharply to get some air. The effort you’ll need to exert to breathe will be quite exhausting and frustrating, and will also increase the amount of carbon dioxide you inhale.
If you really do decide to go with a collapsible snorkel, make sure you choose one from a reputable brand with good reviews so that it serves its purpose and doesn’t make life harder for you.
While snorkels sometimes seem unnecessary and too bulky when you scuba dive (especially the newer designs such as those with a purge valve), they’re a security net for divers and a great emergency tool. For instance, if you’re helping a diver who’s having breathing problems or can’t get back to the boat (or the shore), the snorkel will make it easier for you to breathe as you swim with the other diver at the surface.
Snorkels can also help divers calm down if they’re overwhelmed by particularly rough and choppy waters.
If you do decide to use a snorkel when you scuba dive, make sure you choose the right design (preferably a more compact one).
Scuba diving is our window to catch a glimpse of the underwater world. But since the ocean isn’t our natural habitat, we can only go so deep. Even with all our scuba gear, we can’t go to the very bottom of the ocean.
Every diver needs to know how deep they can go in the ocean without risking their lives. It becomes even more important for deep divers than for beginners.
Deep diving begins at around 18 meters (roughly 60 feet), but the lower limit isn’t as easy to determine. Various factors, such as the diver’s level of expertise and air supply can alter how deep they can go.
The deepest estimated depth recreational divers can reach is around 130 feet but their time to explore is very limited as the water pressure and the intake of compressed air become a threat to the diver’s health. Generally, divers will have around 10 minutes to explore before they need to begin their ascent.
However, with the right gear and practice, divers can go as deep as 1000 feet and explore for a good few hours, but their ascent will be very slow since they have to make decompression stops along the way.
After you cross 6 meters (20 feet) underwater, it becomes necessary for divers to make decompression stops on the way up. It is crucial for the body to dispel the compressed nitrogen to avoid the risk of decompression sickness (characterized by joint pains, etc.).
As you go deeper, the weight of the water and the buildup of compressed nitrogen start taking a toll on your body.
Increasing water weight/pressure starts compressing your lungs and crushing your intake of air. Your heart rate starts to diminish and your blood vessels may burst.
The buildup of compressed air has a laxative effect on your body. Although it feels like you’re floating, this moment of joy can kill you if you’re unable to regain control over your body and return to the surface.
The impact of nitrogen narcosis kicks in at around 100 feet. At this point, you start taking in more air to breathe, which increases your intake of compressed nitrogen.
The nitrogen absorbs very fast into your tissues. It reaches your brain and your nervous system and can eventually make you drowsy or even unconscious. Although there is a standard cap of around 100 feet, some divers reach their limit faster and can experience the effects of nitrogen narcosis earlier, say at around 60 feet or even less.
If you start feeling drowsy during your dive, start your ascent. This will get rid of the laxative effect and by the time you return to the surface, you’ll be back to normal.
The maximum recorded depth any scuba diver has ever reached is around 1,090 feet. The record was set by an Egyptian, Ahmed Gabr who completed his 1,000+ feet dive in the Red Sea and it is considered to be the deepest scuba dive ever.
The diver reached the bottom in around 12 minutes and spent the remainder of the day returning to the surface. The dive started in the morning and ended well after midnight.
During his dive, the diver used up nine scuba tanks and spent 14 hours on decompression stops. He had been a professional diver for around 17 years and had spent 4 years just preparing for his record-breaking dive.
The deepest dive prior to this had been to a depth of around 1,044 feet.
There are different limits set for recreational and commercial divers. With the right scuba gear including a dry dive suit, a scuba tank, gloves, and so on, divers can reach depths of around 1000 feet or more. In fact, with specialized equipment such as an atmospheric suit, divers can reach 2000 feet.
Although some experienced recreational divers might be like the man who set the world record for the deepest dive, there are some basic depths set by dive institutions:
Commercial divers go underwater for numerous purposes:
Usually, commercial divers go to a depth of around 200-300 meters, especially if any construction or repair work is involved.
There is no fixed depth where we can say for sure that a diver will be crushed once they cross a certain depth. Most recreational divers don’t generally go beyond 130 feet, but commercial divers manage to reach depths of 2,000 feet with the help of atmospheric suits. There have been recreational divers who have reached depth of 1000 feet and more and they were perfectly alright afterwards.
The main thing to look out for is being crushed due to the increasing weight of the water. The water pressure can squeeze your lungs and completely constrict your breathing till you’re dead. You also run the risk of experiencing nitrogen narcosis since you will have exceeded your decompression limit.
With basic open water certification, a diver can dive to a maximum depth of 18 meters (around 60 feet). With further training, you can obtain the Advanced open water diving certification that will allow you to dive to a depth of 30 meters (around 100 feet).
With even more advanced training, you can go even deeper to around 40 meter (130 feet) or more. These limits are set for recreational divers, not professional and commercial divers.
To dive to such great depths, you will need to have a special mix of gases in your air supply to avoid being taken over by the narcotic effect of the compressed nitrogen.
For very deep dives, you need a special gas mix to help you breathe comfortably and combat the effects of nitrogen narcosis. To reduce the amount of nitrogen in the tank, the gas mix incorporates helium or hydrogen.
The traditional mix of a scuba tank contains compressed air which is a blend of 21% oxygen and 79% nitrogen. This is only suitable till around 40 meters (130 feet). At around 56 meters (184 feet) and beyond, compressed air becomes toxic for the human body and nitrogen narcosis sets in).
Pure oxygen tanks are rarely used by scuba divers because oxygen has a tendency to become toxic underwater. Some technical divers may use it, but they have to keep a very close eye on their decompression stops to avoid serious injuries.
Here are some of the different types of gas mixes deep divers can make use of:
Nitrox mixes contain 22-40% Oxygen with the most common blends having 32-36%. However, Nitrox mixes are NOT meant for deep-diving. They are meant for shallow diving and their main purpose is to increase the decompression limit of the diver.
They do have a lower nitrogen content which means that your body absorbs less compressed nitrogen. The high oxygen content will still make the mix toxic once you cross the aforementioned depth.
Recreational divers start to use Nitrox more and more. One thing to remember is to have the necessary gear to deal with it. Not every dive computer can deal with Nitrox for example!
Trimix contains a mixture of oxygen, nitrogen and helium. We’ve already established that nitrogen has a narcotic effect on the body as we go deeper, which is where the helium comes in. helium, being an inert gas does not react with the body and allows divers to go deeper without feeling drowsy.
Trimix cylinders may contain 21% oxygen, 44% nitrogen and 35% helium (some contain 45% helium). With the trimix cylinder, divers can go as deep as 60 meters (197 feet).
If you intend to go even deeper, you need a hypoxic trimix cylinder (contains 70% helium). This will allow divers to reach around 100 meters (328 feet) without the gas supply becoming toxic.
Trimix cylinders are quite expensive and are generally used by technical divers.
Commercial divers prefer heliox over trimix. The heliox mix can be used for dives up to 300 meters (984 feet), but if you want to go deeper, the helium in the tank will have to be replaced with hydrogen since the helium will start having a narcotic effect.
This mix is known as hydrox and it is a combination of hydrogen and oxygen. Commercial divers such as those laying down pipelines for gas or oil rely on hydrox tanks to breathe underwater.
It is highly inadvisable to dive without your scuba gear, but many daredevils and scuba enthusiasts have faced the challenge of free diving and have set world records. A professional diver managed to reach 328 feet during a diving competition!
However, we would like to point out again, that this is unadvisable. Once you reach around 300 feet, the water pressure will become so intense that it will start squeezing your lungs, slowing down your heart rate and even shrink your blood vessels. It will even have a narcotic effect on your body, making you feel drowsy and spaced out.
A trained diver can manage such a dive in a short time span (around 5 minutes), but it is still very risky and not recommended.
The Titanic rests at a glorious 12,000+ feet underwater and while visits have been made to the wreckage, you can’t dive there. Submarine tours can take you to the ruins, but be warned, it’s not as exciting as you think. The submarine fits 5 people, has a very basic bathroom facility, and the entire journey can set you back around USD 100,000+ (if you’re going on the one-week tour)!
Even though you won’t be diving to the shipwreck, you still need to pass a physical fitness exam before you’re ready to make the journey. Since the most a human can dive to around 2,000 feet (and that too with a special atmosphere suit), trying a 12,000 feet dive is a death wish.
In fact, the number of people who have visited outer space is greater than those who have visited the Titanic shipwreck.
Saturation diving revolves around the premise that the pressure of the gas dissolved in your blood and tissues is equivalent to the gas in your lungs. If a diver reach a depth of say, 300 feet and stays there, the body can no longer absorb gas and reaches saturation point. At this point, decompression stops will be the same whether the diver spends a minute or a day more underwater.
Saturation divers use a liquid mix of perfluorocarbon to breathe so that no gases get absorbed into the body. In fact, research indicates that it might be possible for humans to dive as deep as 3,000 feet with this liquid mix.
Large-scale underwater construction or repair projects are completed by saturation divers. These divers spend a few days out at sea, and when they’re not underwater, they reside in a high pressure ship or barge.
As a recreational diver, you can’t go very deep, but you can still go deep enough to explore the wonders and mysteries of the ocean. Dive institutions such as PADI provide certification for cave diving, exploring shipwrecks, and so on to enrich your diving experience.
Although commercial divers can go much deeper into the ocean, the experience eventually becomes less than magical for them. Spending a few days in a wet abyss of the ocean can take a toll on divers, physically and mentally.
If you’re ready to explore the great blue beyond, find a diving buddy, sign up for lessons and get started!
Many people believe that the earlier you get your children in the water, the sooner they’ll become more conscientious about their surroundings and eliminate any irrational fears about the water. Most dive institutions start providing scuba diving lessons for children as young as 10 years old.
How old do you have to be to scuba dive? The minimum age to get certified by PADI or SSI is 10 years to get a junior certification. The BSAC requires a kid to be at least 12 years to get certified. There are further restrictions on how deep a kid can dive to ensure their safety and well being.
Many dive agencies offer scuba diving courses for children as young as eight years old, but these are restricted to confined spaces such as swimming pools. These do not provide certification to dive in open waters such as in the sea or a lake. If you’re not 10 yet, these lessons can be a great way to expose your child to the world of diving. It’s also a fun summer activity.
These courses teach children basic techniques such as equalizing their ears underwater, signaling in case of emergencies, and so on. Important lessons are broken down and simplified to help children understand important elements of scuba diving such as:
These pools have a maximum depth of around 4 meters (12 feet), and once lessons are over, children are allowed to play around in the water (with adult supervision).
If your children are old enough to enroll in classes for an Open Water Dive Certification but aren’t ready for it yet, they can sign up for these basic classes to get comfortable with the water and their equipment.
You need to be at least 10 years old to start taking scuba lessons from a PADI instructor. Divers start with the Open Water Diver Certification, and divers less than 15 years old who complete this attain the status of Junior Open Water Diver. These divers are only allowed to dive to a depth of around 12 meters (40 feet) and even then, they need to be accompanied by an adult (in case of emergencies). Even for this junior certification, students use the same material and have the same lessons that are taught to adult divers.
Once divers reach the age of 15, they can dive to 18 meters (around 60 feet) with the same Open Water certification.
Divers taking lessons online need to be at least 13 years old to be taught by a PADI instructor.
For children who are not 10 yet, PADI offers two programs: the Seal Team and the BubbleMaker that are a fun and safe way to introduce children to scuba diving.
Just like the requirements for PADI, potential divers need to be at least 10 years old to be taught by an SSI (Scuba Schools International) instructor. Again, similar to PADI, before the age of 15, divers are identified as ‘juniors’ and are upgraded once they reach 15 years of age.
Similar to PADI’s Seal Team and Bubblemaker programs, SSI offers the SSI Scuba Rangers program for younger children.
MSAC (British Sub-Aqua Club) has stricter requirements than PADI and SSI. Children need to be at least 12 years old to sign up for scuba lessons.
12-14 year-olds can obtain junior certifications of adult courses such as the Open Water Diver certification, rescue diver certification, and even some of the more advanced, specialty courses.
The average depth these divers are allowed to descend to is around 60 feet (although some institutions allow divers to go to around 72 feet). All junior divers must be assisted by an adult. Once they reach the age of 15, their certification is automatically upgraded (without any additional testing).
Children need to be accompanied by an adult, even if they have an Open Water Diving certification. If you are certified and want to take your child scuba diving, you can do so. Make sure to pay attention to your child and not just focus on your own dive.
There have been no experiments to test the effects of water pressure, decompression sickness, and others on children since they are not only unethical, they are also life-threatening. However, there is plenty of research that indicates that there are certain psychological and physicals risks involved in letting children scuba dive.
Not all children can handle the stress of being underwater. Some core factors need to be considered before you enroll your child in a scuba diving class:
Although you have to consider your child’s learning capabilities before getting them started on their dive lessons, scuba diving can be a great activity for your children:
Certain features about the biological makeup of children make them more susceptible to the risks of scuba diving than adults:
Apart from affecting a child physically, scuba diving can also be risky for children since their minds are still developing:
Although there are a few risks involved for children who take up scuba diving, every child is different. The decision of whether your child scuba dives or not is dependent on his/her mental and physical capabilities, the dive institution and whether or not your child even wants to learn in the first place. If your child loves the water and you feel like they’re ready scuba dive, enroll them in a PADI or SSI course, or any other renowned dive institution in your area.
Scuba tanks are the only source of air for scuba divers. When you’re underwater, you have to keep an eye on your air supply to ensure that you return to the surface before you run out. But how long does a scuba tank last? The amount of time it takes for your scuba tank to become completely empty is based on a number of factors such as the depth of your dive, whether you’re a pro or a beginner and the size of the tank you’re using.
How long does a scuba tank last? That depends on a number of factors including the tank volume, depth of your dive as well as your air consumption. There is no clear answer that can be given as the variables have an enormous impact on the length that your tank will last.
From depth to tank size, a number of factors affect how long the air in a scuba tank lasts:
The standard scuba tank holds around 80 cubic feet of air that is compressed to around 3000 lb./PSI. Tanks may be made of different materials to cater to the many different types of divers. Deep divers ideally opt for tanks with a higher internal volume. Divers who don’t require too much air may opt for a smaller tank, which is lighter and easier to carry underwater. Generally, a tank with a high volume tends to last longer underwater.
A diver’s air consumption rate determines how long a standard air tank will last them underwater. Tall (and large) people generally need a greater air supply than petite (and short) people. Apart from size, several factors affect an individual’s air consumption rate such as: stress level, expertise, buoyancy control and the effort exerted in a particular dive. Instructors usually guide divers to breathe slowly and deeply to lower their air consumption rate.
When your body is in good shape, your muscles are relaxed and you don’t need to exert extra effort to breathe properly. This also explains why most basic dive certifications start with basic swimming classes before the students are fit enough to dive deeper into the water.
Water pressure increases the deeper you go in the water. The greater the pressure, the denser your environment. In the water, the deeper you go, the denser the water becomes, and since gas molecules are so tightly packed, you need to work harder to regulate your breathing.
Even if you’re in waters as shallow as 10 meters deep, the pressure is double and you need to put in twice as much effort to breathe. At 20 meters, the pressure is tripled. The deeper you dive, the more effort you need to exert to breathe, which means that you consume your air supply faster.
At around 10 meters, a diver’s tank can, on average, last for about an hour. At around 40 meters, the supply will only last for a few minutes. Professional divers can make their air supply last twice as long by controlling their breathing (beginners tend to breathe harder as they try to get the hang of being underwater) and their motion to save as much energy as possible.
Scuba tanks vary in size and the size determines how much air supply you’ll have underwater and how long it’ll last you. The standard cylinder size is around 12 liters (200-bars).
As mentioned earlier, a standard 6.5 LB scuba tank holds around 80 cubic feet of compressed air at 3000 LB/ PSI. commercially, scuba tanks are identified based on their volume in liters. The standard is around 12 liters, which is a little less than the afore-mentioned values, but it is easier to round off the numbers. Tanks also come in smaller and bigger sizes such as 8 liters, 10 liters, 15 and 18 liters.
The larger the tank, the more air it will contain and the longer your supply will last. Of course, you can’t just base your decision on the tank size. If you’re unable to carry the weight, it’ll be impossible for you to move around if you’re lugging a 15-liter tank with you. Physical strength and size must also be taken into account during tank selection. Underestimate your strength to avoid facing problems underwater. It is a good idea to test the weight of the tank on land before diving straight into the ocean.
For beginners, it is advised to start off with a smaller tank, especially since they’ll only be doing shallow dives initially. Once they move on to deep diving, they can opt for larger tanks.
Tanks have a stamp near the top edge to signify how much compressed air they can hold. The greater the air pressure in your tank, the longer you’ll be able to breathe underwater. However, there’s a catch.
By consuming high-pressure air, you are likely to enter your decompression zone much earlier than the standard depth (around 20 feet). If you plan on using high-pressure air during your dive, you’ll have to keep a close eye on your dive computer (or your dive tables) to ensure that you make the necessary decompression stops and avoid the risk of getting decompression sickness (characterized by joint paints, etc.).
Smoking and other lung-related problems like asthma greatly impact a diver’s body. It doesn’t matter whether you smoke one cigarette or one packet a day, it will impact your breathing ability underwater.
Cigarette consumption reduces the oxygen content in the body and increases the intake of carbon monoxide. The human body naturally generates a small amount of carbon monoxide, but the amount inhaled through cigarette smoking is significantly greater. It fixes itself onto your red blood cells and takes up the space that is generally taken up by oxygen in a non-smoker’s body.
Smokers may face shortness of breath on land, which only becomes more pronounced once they’re underwater. Smokers may find it difficult to breathe through their contracted lungs and are likely to use up their air supply in half the amount of time it would last a non-smoker.
Twin tanks are becoming popular among recreational divers nowadays. Essentially, twin tanks function the same way as a regular tank and have a single control source, but if you switch off the supply from one tank, the other will still keep supplying air. This makes divers more self-reliant, especially in cases of emergency.
Moreover, a twin tank provides a greater gas supply without increasing the weight. Twin 8-liter tanks supply more air than a single 12-liter tank and the two roughly weight the same.
For divers diving multiple times in the same day, twin tanks are a more convenient option. This is because where a single tank diver must leave their tank with its remaining supply on the shore and carry a fresh tank, a diver with a twin tank can keep diving with the same pack if one is full and the other still has some supply remaining. This makes diving with a twin tank more economical.
Twin tanks also feature a back plate and a wing buoyancy device that help divers maintain their horizontal position underwater and make them glide better.
There’s no ballpark figure for how long a scuba tank lasts. It may last for 10 minutes, an hour or even an hour and a half based on many variables such as your tank size, your physical strength, the amount of time you’ve been diving for and the depth to which you’re diving.
Deep divers tend to use larger tanks and have the proper training to regulate their breathing so that they don’t waste their air supply.
For newbies still trying to get comfortable in the water, small tanks are ideal. Your dive instructor will provide with all the necessary information on the right way to breathe underwater (slow, deep breaths) and a rough estimate of the amount of time your tank will last you at a given depth.
Just remember, that your air supply is not the only factor that determines how long you can stay in the water: you need to be aware of your decompression limit to avoid consuming too much compressed nitrogen, which can lead to decompression sickness.