Everything you need to know about scuba diving in 2023

Our indepth guide to Scuba Diving

Basic Scuba Diving

Ok. You’ve seen how good scuba diving looks in the movies, but making it look good takes some experience and technical prowess. Like Robert DeNiro in Men of Honor prowess. No worries. We’ve collectively cultivated some of the best habits gleaned from life underwater for you to adopt in order to make it look good and feel even better at the same time.

If you want to stay longer underwater or want to learn better finning techniques, we got you.

After getting a taste of the underwater world it’s only natural not only to want to do it better but also to want more of it. Fortunately, others have been here before and there’s the innovation to prove it.

NITROX and rebreather apparatuses make things a little more technical but present the possibility for a payoff in the form of longer periods underwater, giving more time and security to explore caves in harder-to-reach areas at slightly more inaccessible depths.

Diving and Taking Care of the Environment

Scuba diving and snorkeling are what it is because of the dynamic natural aquatic environment. As ecosystems are punished by overfishing and pollution, conservation of the oceans is a necessary part of maritime activities making us acutely aware of the need to do more.

Bleaching of coral reefs due to warming temperatures is one visual reminder of the impact human industry has on not just the air we breathe but also on the oceans. It is the sea that absorbs the excess burden of our collective activities mitigating climate change as much as it can until it too falls out of balance.

Check out some info on how you can help conservation efforts. Join others striving to protect the integrity of marine ecosystems.

Check out some organizations that are making a difference. Find out how you can do more.

Skin diving & Freediving: stripped-down diving

Before there was scuba, there was skin diving. Skin diving is swimming underwater while holding your breath for leisure or fitness. Freediving is the competition-based discipline of divers holding their breath for as long as possible to swim as deep or as far as possible.

Whereas snorkeling is the total leisure approach to observing the aquatic universe from the surface, skin diving and freediving demand dealing with the hydrostatic pressure that increases as you dive deeper. Even though there’s no tank you need to practice equalizing, maybe even moreso because you’re holding your breath and it’s air that is getting constricted.

See our guide to finding the right mask, snorkel, and fins.

Scuba Diving and Snorkeling With Sharks

It’s a fairly well-accepted truth that sharks aren’t as dangerous as the movies make them out to be. Sharkwater, a documentary by conservationist Rob Stewart (read his obituary) succeeded in bringing this truth to a wider audience and since then swimming with sharks has boomed. But so has awareness of the role these ancient species play in creating balance in the ocean.

Divers and snorkelers who share the water with sharks experience exhilaration and awe. It’s normal to be insecure about sharks because they are predators and some of them can appear menacing. But the truth about sharks reveals that they are in fact preyed upon by human activities including industrial fishing, demand for shark products in cosmetics and by restaurants, and, of course, climate change affecting their habitat.

73 million sharks are slaughtered each year for their fins alone, with the total number much higher when fishing is included. As awareness and understanding increases so too does our ability to help conserve the natural world.

Not all sharks sit atop the food chain. A giant moray eel though has bit off more than he can chew.

As scuba divers and snorkelers increasingly encounter sharks, demand for cage diving with great white sharks and shark safaris are also on the rise. Shark feeding too has become wide-spread, with debate swirling around from different points of view. Do they encourage shark attacks, for example? Not likely.

Shark diving is safe

Whether it’s wise to feed sharks will continue to be debated. It is clear from data that it is not particularly dangerous to kit up and swim with sharks as long as the basic guidelines are followed. Being safe and maximizing fun is why rules exist in the scuba world.

If you’re going to swim with sharks, do your research on the dive center and continue to behave like the responsible diver that you should be to help maintain the ocean and carry-on the spirit of people like Cousteau and Stewart. Meanwhile, check out this shark tracker to see how far they swim.

History of Diving

It’s natural to want to swim underwater. History has many anecdotes romanticizing the earliest divers.

Fishing, finding pearls and sponges, salvaging supplies or merely recreational activities have attracted humans to water, drawing them under the waves. The earliest stories of freedivers appear in paintings and literature, like Homer’s The Illiad.

Scene from a 5th century BC Tomb of the Diver

Breathhold divers or freedivers have otherwise been supplying marine products since 4,500 BC. Especially sponges were valued for their use washing, as canteens, and to dress wounds. The Greeks later established rules governing the diver’s right to compensation for salvaged goods, with a greater percentage calculated for greater depths.

According to “the first historian” (or liar as he is also known), Herodotus recounts how, during the second Greco-Persian War, a captured Greek soldier hopped overboard with a reed tube he used as a snorkel to hide below the surface until he could sabotage the Persian ships.

Homer describes squads of divers, navy seals of a sort, active during the Trojan War. No doubt recreational and commercial interests drove innovation, but military imperatives did too.

Eventually, snorkelers in the Persian Empire around 1300BC began to use polished tortoise shells strapped over their eyes to see underwater. This made spearfishing and locating lost items–and subsequent freediving for salvage–vastly easier than it had previously been.

To defend against submersed soldiers, the Roman Empire started to use metal anchor lines that could not easily be sheared by attacking divers.

Because the Mediterranean Sea in modern times as it was in ancient times has always hosted constant maritime traffic in seafaring trade, there is an amazing amount of wrecks. Today this offers great diving opportunities but back in the day reclaiming items from a shipwreck by freediving wasn’t practical.

Leonardo da Vinci’s 16th century scuba concept

Who else but Leonardo da Vinci could develop the concept and see the practical potential of what basically exists today in the commercial diving sector. The renaissance man designed a diving suit that had a flexible snorkel with pig-skin joints that were reinforced by steel rings to withstand the pressure of depth. A wineskin filled with breathable air, much like an artificial lung was incorporated into his system.

Da Vinci’s scuba suit was never used, nor was it taken up by any of his contemporaries who likely couldn’t envision or foresee the possibilities of the product. In 2003 his concept was proven by ……… in shallow water, but still, the story of diving remained stunted.

Even though Aristotle describes the diving bell used by sponge hunters harvesting underwater animals and describes how Alexander the Great himself had used them for war and scientific inquiry, it is not until 35 years after Da Vinci’s diving suit that innovators begin to take up the mantle.

Guglielmo de Lorena installs a glass port in a diving bell and recovers works from the wreck of one of Roman Emperor Caligula’s floating pleasure palaces, sunk in the 1st century AD. Rumors of a vast vessel lying at 60 feet below Lake Nemi and containing splendid artifacts escaped liquored fishermen loose tongues, who sometimes got lucky with their hooks.

Hearing the tales of treasure in 1535 de Lorena and his partner Francesco de Marchi used their new diving bell to recover statues and treasure from the massive, submerged vessel belonging to the mercurial and villainous Caligula. A treasure chest the length of an Airbus A380, there was vast wealth to be had from discoveries that lay just beyond reach, but the technology was still lacking to get at it.

It’s in the 1600s that the diving bell really begins to develop practical innovative design alterations. Though these new ideas inspired experiments, most were in fact merely designs that were incorporated into subsequent models years later.

The alchemist and painter Franz Kessler apparently built an actual diving bell in 1616 while creating pamphlets and “how-to guides” in the Holy Roman Empire.

The Renaissance had returned the sense of industry to innovation in Europe, empowering the curious and bold to reap rewards from their ideas.

Working from a diving bell between 1663-1665 Albrecht von Treileben successfully managed to salvage cannons and treasure from the sunken Flagship Galleon, Vasa, a warship which flopped over in Stockholm’s harbor immediately into its maiden voyage in 1628.

The Nuestra Señora de la Concepción, a Spanish galleon with vast riches remained tantalizingly close to the desires of intrepid treasure hunters, but still out of their reach until William Phipps set sail with the latest underwater diving technologies in 1687.

Salvaging from the sea. William Phipps used a diving bell to locate sunken spanish treasure from wrecks in the carribbean. The booty was then connected to top-side cranes that lifted the items onboard the floating ships.

Phipps reaped recompense along the lines of £200,000, a King’s ransom in those days worth $48 million in 2020.

And not just entrepreneurs but artists too, inclined to sea the magic of the ocean and the secrets therein contained extolled the wonderous possibilities suddenly emerging.

The 1663 Ballad of Gresham College illustrates the enchantment with which the public at large were affected:

A wondrous Engine is contriveing In forme, t’is said, much like a Bell, Most usefull for the Art of Diveing. If ‘t hitt, ‘t will prove a Miracle; For, gentlemen, ‘t is no small matter To make a man breath under water.

And so invention was carried further by imagination, albeit with stuttering stops-and-gos. And science was beginning to reveal some interesting facts about the effects of diving on human physiology.

In 1670 English scientist Robert Boyle proved that reducing ambient pressure in living tissue caused bubble formation that blocked the passage of air. He subjected a viper to a vacuum-sealed room, depressurized it, and produced the first known case of decompression sickness. He observed bubbles forming in the snakes eyes.

Innovation was accelerating.

Dennis Pepin drew up plans with a system of pumps and bellows in 1689 to maintain indefinitely fresh air inside his bell.

Dr. Edmond Halley (who named a famous comet) envisioned a diving bell in 1691 with windows for undersea exploration. His model received replenishment of air in the form of weighted and sealed barrels that could be sent from the surface.

Halley’s Bell gave him and his divers more time at greater depth, a fact that he demonstrated in the River Thames, diving to a maximum depth of 60 feet (18 meters) for close to an hour and a half.

The first diving machine was built by another Englishman, named John Lethbridge. His contraption was an oak barrel with a porthole window and holes for his arms and small, to move around at a maximum depth of 50-55 feet (15-18 meters) for as long as 34 minutes.

John Lethbridge’s diving machine was half diving suit, half submarine.

Lethbridge was able to recover items from wrecks without any coordination from the surface, gaining quite a bit of success but enjoying very little renown for his efforts.

In 1771, William Seaton constructed a pump that could convey air from the surface to divers down to 60 feet deep much like Pepin had envisioned a century before. Up until then, divers could only descend so deep using a diving bell, leaving the encasement through the wet, open bottom to collect items at depth and return to the bell.

Thus while they could in principle stay at depth longer Seaton’s pump allowed an unencumbered diver to move about better, which was especially useful for bridge repairs as well as salvage.

A year later, the Frenchman Sieur Freminet went further than his English counterpart, inventing an air recycler to give the diver more time underwater. While fortune favored the bold, safety didn’t supply them succor. These pioneers pushed the boundaries and, in the early days, often paid the ultimate price.

Freminet perished after 20 minutes into a plunge having dived in with unrealistic expectations of his machine. He miscalculated its performance capabilities and didn’t know enough about gas and pressure exchanges. He ran out of air, not understanding the amount of carbon dioxide we exhale, nor enough about the rebreathing scrubbers that later inventors would develop.

Using Seaton’s pumps and improving upon Pepin and Halley’s designs, the Scotish confectioner Charles Spalding built a bell in 1775 with a system of levers and balance weights to lower and move the device. Rudimentary lines were utilized to signal to the surface direction or navigation.

The 1775 Spalding Design, still with wet bottom.

Risk reward remained two fickle friends for the trail-blazing Spalding. He and his nephew suffocated in 1793 off the Dublin coast while salvaging in the bell.

But now there were experiments with apparata that freed divers from the diving bell began appearing more frequently. More importantly, technology was making it possible for a diver to carry his own air with him, independent of the surface. Freminet’s suit was proof of concept and an encouraging waymarker for others to follow.

In 1825 William James invented another self-contained breather with an air-filled iron belt-like apparatus attached to a copper helmet. There was contained in the belt enough air for a seven-minute dive.

James’ suit allowed the diver to regulate his air using a hand-held valve, representing what some consider the first proper, working scuba suit. Purged air escaped through a valve in the helmet.

Mobility was still a problem and so too was the increasing number of divers suffering decompression sickness. Commercial divers, known as caisson workers at the time, suffered ear pain and limb stiffness.

In 1837 a flexible waterproof suit designed by Augustus Siebe still used air pumped from the surface, but improved by leaps and bounds the diver’s mobility. His standard diving dress or standard rig allowed the diver to bend over or lie down without the threat of flooding the helmet.

And the flow through his closed dress could be adjusted, thus his buoyancy could be controlled much like the BCD functions today.

With the use of Siebe’s closed dress suit among other competitors, England’s Royal Navy set-up the first diving school in 1843 and with that diving moves from amateur to commercial to professional and military. It meant data began being collected more systematically.

It was observed by B. Pol and T.J.J. Wattelle in 1847 that recompression could alleviate symptoms of DCI, marking the first occasion for the practice so common today. They noted a connection between symptoms, depth and duration of exposure to the intensity of the decompression. They also noted that divers between 18-26 were more able to withstand conditions leading to DCI.

Another major advance accompanied Rouquayrol and Denayrouze’s demand valve and diving rig. With compressed air on the diver’s back connected to a pressure regulator their suit further improved the mobility of a diver and inspired Jules Verne to include such a diving dress in his 1875 book, 20,000 Leagues Under the Sea.

An illustration from Jules Verne’s 20,000 Leagues Under the Sea.

Verne’s book combined with the commercial applications demanded everymore of divers’ ability to withstand depth, but the physical limitations of the body as well as the technological gaps in gear were still hindering major advancements.

It is the aqua-lung that Jacques-Yves Cousteau helped develop with his physicist friend Émile Gagnan that revolutionizes diving. Cousteau was a navy officer pushing the boundaries of diving and acutely aware of the technological limitations that kept him from exploring the oceans as he wanted.

One initiative to overcome these borders was the invention of the rubber suit he co-developed to maintain body heat underwater in order to dive the mediterreanean. Because of his diving mobility he was able to prove the allies with detailed intelligence on axis naval activities.

But still limitations were preventing further development of underwater exploration

Up until the mid-20th century, the problem for diving was the same as it had been essentially since forever.  Breathable air, unless it was continuously pumped from the surface ran out too quickly before a diver could make it to depth and safely back again. There was hitherto no method to prevent the gas from constantly escaping and leaving the diver high and dry–but still low and wet.

Meanwhile Gagnan was developing a fuel injection mechanism for the internal combustion engine during the second world war. The new regulator mechanism was a direct response to fuel shortages due to Nazi German requisitions. This development made fuel consumption drastically more efficient.

As it so happens, Gagnan’s boss had a son-in-law who was looking for an automatic demand regulator mechanism to better administer his scuba tanks and increase dive time. Once the two were acquainted and after a few weeks of tinkering the technology to adapt it to diving, the Cousteau-Gagnan Regulator was patented in early 1943.

This open-circuit regulator provided the Frenchman with air through a mouthpiece as he inhaled, rather than as a constant escaping flow. Much more was possible including making underwater movies, which he, Phiippe Tailliez and Frédéric Dumas did in July 1943.

Épaves, a 28-minute documentary about shipwrecks in the Mediterranean was the first move made by scuba divers. 15 wrecks at depths of up to 15 meters were explored and when the film was released in 1946 it won an award at the inaugural Cannes Film Festival.

During filming, Dumas went to a record depth of 203 feet (62 meters) and lived to talk about, which was, thanks to the aqua-lung, finally possible.

Not only could he and his fellow-divers stay down longer but the improved safety of the apparatus made it commercially viable.

Following the cessation of war the Scaphandre Cousteau-Gagnan or CG45 (refering to the initials of the men and the year of the model) went on sale to the public by Air Liquide. Cousteau trademarked the name Aqua-Lung and began licensing the product out for manufacturing by the American division of Air Liquide called U.S. Divers.

Cousteau pictured above with an aqua lung apparatus.

But since he made his first voyages down below producing videos of his underwater explorations, the recreational diving industry has expanded with increased safety and convenience.

Aqualung is still around today, one of the biggest producers of regulators – owned by PADI – but so are an ocean of other open-circuit products. Since NAUI and PADI opened up scuba diving to the masses in the 1960s scuba diving has blossomed and is booming.

Now there are between 2.7 and 3.5 active scuba divers in the United States along with an additional 6 million world-wide. Closed circuit rebreathers, Nitrox and other gas mixtures, as well as multiple tanks allow for divers to continue to push the envelope of what is humanly possible.

The deepest a scuba diver has descended to is currently 1,092 feet (332 meters). It took 12 minutes to get down and 824 (almost 14 hours) to slowly ascend to the surface. Ahmed Abdel Gabr used three different mixtures of air through a rebreather to achieve this feat.

While most recreational divers remain below for less than an hour, Gabr’s accomplishment demonstrates how human obsession with the underwater world continues to fire our imagination and compel us deeper into the water for longer periods of time.

Perhaps one day science and technology may make it possible for someone to spend more time underwater than above.