Welcome to scubasites, we hope you enjoy your time here. Scubasites is dedicated to providing information on scuba diving and the scuba equipment that is needed to dive safely and successfully.
The earliest form of scuba diving comes from Greek history. It is said that during the naval campaign of King Xerxes I of Persia against the Greeks, a Greek warrior named Scyllis was taken captive. During his captivity he was taken onboard Xerxes’ ship and learned of an impending surprise attack on the Greek navy. Upon learning this, Scyllis seized a knife and jumped overboard. The Persians could not find him in the water, and they presumed that he had drowned. Scyllis actually used a hollowed reed as a breathing tube. During the night he returned to the anchored Persia fleet and used his knife to cut the ships loose from their moorings, thus preventing the Persian attack.
True or not, this story illustrates the first example in history of underwater breathing. Since the dawn of man we have been fascinated by the idea of being able to survive under the water. Whatever our motives- exploration, conquest, research, food, or just fun, almost everyone has entertained a daydream of living underwater. The historic search for the means to do so has been full of false starts and dead ends, but perseverance has paid off, and modern techniques allow divers to work for hours, sometimes longer at great depths.
A modern scuba set consists of a pressurized tank of gasses (not air!), a delivery system with a mouthpiece and atmospheric pressure sensor, a wetsuit or dry suit, scuba fins or flippers, and of course a face mask. The scuba tank is filled with different mixtures of gasses depending on the depth of the bottom of a planned dive. Recreational diving mix is suitable to depths of about 130 feet, and is similar to the air we breathe. It is about 79% nitrogen and 21% oxygen.
The pressure sensor on your air delivery system adjusts the pressure of the air fed to your mouthpiece so that it matches the pressure the water is exerting on your body. Without this adjustment it would become difficult to breathe just a few feet under the surface, and by 20 feet down, it would be impossible. Your wetsuit keeps your body warm in moderate water temperatures, for extended exposure to colder temperatures a dry suit is needed.
Your scuba mask allows you to see underwater. Water refracts light at a much higher rate than air does. If you open your eyes underwater without a mask you will notice wild distortions in any movement. This is because the body of water acts like a gigantic extended cornea, bending the light waves before they enter your actual eye. The scuba mask minimizes this distortion.
Scuba fins and accessories complete your setup. The fins allow you to maneuver underwater with more power and precision. Accessories help you do whatever it is you want to do underwater. Waterproof cameras allow for photographs or movies to be shot from depth, scientific equipment allows researchers to monitor ocean life and conduct experiments.
There are fantastic scuba travel destinations, whether it’s the Florida Keys, the tropical reefs of the Caribbean, the Hawaiian Islands, the Great Barrier Reef, or even aquatic caves; there is a destination fit for your budget and tastes.
- Scuba Accessories – Scuba accessories provide a chance to personalize your scuba ensemble.
- Scuba Dive Gear – Scuba dive gear will get you where you’re going in comfort.
- Scuba Diving Equipment – Scuba diving equipment allows you to breathe while underwater.
- Scuba Equipment – Scuba equipment gets you into the water and a whole new world of beauty.
- Scuba Fins – Scuba fins help you control your movement underwater.
- Scuba Gear – Scuba gear comes in a wide array of types to suit your tastes.
- Scuba History – Scuba history is a fascinating story of mankind’s efforts to explore the largest regions of our earth.
- Scuba Mask – Scuba masks protect your eyes and nose from the water while diving.
- Scuba Set – Scuba sets are readily available from many vendors.
- Scuba Store – Scuba stores will have helpful experts to answer any scuba related questions you may have.
- Scuba Tanks – Scuba tanks allow you to breathe underwater.
- Scuba Travel – Scuba travel is limited by air supply and decompression times.
The most easily identifiable piece of diving equipment is the scuba tank. This is a canister of compressed air that the diver takes down with them so that they can breathe underwater. Combined with a tube and a mouth piece, the scuba tank is the core of any set of diving equipment.
Scuba tanks contain a mixture of compressed oxygen and other gasses. Depending on the type of diving done, the expected amount of bottom time, and the breathing system the mixture of gasses differ. For open circuit breathing systems the typical mixture is nitrogen and oxygen in a ratio of 78% to 22%. This is a safe mixture to use up to a depth of 120 feet below the surface.
For deeper diving, scuba tanks are filled with other mixtures. Some examples of deep sea diving air mixtures are hydreliox- a mixture of helium, hydrogen, and oxygen; and trimix- which is a nitrogen oxygen mixture with helium added to increase the safe bottom operation of the mix.
The reason for adding helium to regular breathing air is that both nitrogen and oxygen become toxic to the body if ingested at a high enough pressure. As you descend deeper underwater, the air intake system of your diving suit adjusts the pressure of the air to the surrounding water pressure. At a certain concentration oxygen and nitrogen begin causing problems with your body’s nervous and respiratory systems. Adding helium to an air mixture allows a diver to go deeper before hitting the toxicity threshold because there is a lower concentration of both oxygen and nitrogen in each breath.
You are a novice scuba diver and you’re about to embark on your first dive, what do you wear? Scuba equipment of course! Scuba is actually an acronym that stands for self contained underwater breathing apparatus. Try saying that five times fast and you’ll immediately understand why the word scuba became so popular. What the novice may not know is how recently most of modern scuba equipment was born.
If the modern scuba movement can be said to have parents, they would undoubtedly be Jacques-Yves Cousteau and Émile Gagnan. Cousteau was a French navy diver, and Gagnan was a French-Canadian engineer. In the years following WW II Cousteau worked extensively with aqua lungs. Aqua lungs were a 19th century invention that allowed a diver to breathe underwater from a compressed canister of air. Cousteau and Gagnan improved upon existing designs by adding pressure adjusting delivery. This was the first attempt at solving the depth issues suffered by divers.
Pressure adjusting delivery is an important aspect of modern scuba equipment because it allows the system to adapt to different ocean depths. The human lung has difficulty working against outside pressure, at a depth of as low as 8 feet below the surface, breathing through an unpressurized tube becomes difficult. Diving of any great depth with breathing assistance requires that you can take in air at the same pressure that the water is exerting on your body.
The invention that allows all this to be possible is a piece of scuba gear called a diving regulator. The diving regulator consists of a series of valves between the air supply and a diver’s mouth piece. The valves lower the pressure from the extremely high level found in the canister down to a breathable pressure. The last valve is attached to an ambient pressure sensor which allows it to ramp the pressure up as a diver descends.
Aside from his work in modernizing scuba equipment Cousteau also was an active promoter of diving. He shot underwater film, did undersea archeological digs, wrote books, and conducted research the world over. He was very active in promoting and improving scuba until his death in 1997. He left behind more than 120 documentaries and 50 books, as well as the environmental protection foundation he founded.
While the delivery of air to the body at ambient pressure was a major innovation in scuba equipment, perhaps a bigger shift occurred in the move away from compressed air. Even before Cousteau’s time governments were researching the use of other gas mixtures than those found in air to aid deep sea diving. The problems they were trying to surmount were the toxicity of oxygen and nitrogen at high pressure. Past the pressure of about 1.5 atmospheres nitrogen becomes toxic in its natural concentration of 78% of air. Shortly thereafter a concentration of 21% oxygen also becomes toxic. Early deep sea diving research attempted to reduce the concentration of oxygen below normal atmospheric levels. They found that by reducing the oxygen to 16% concentration in a mix, the pressure at which the oxygen became toxic became correspondingly higher. Modern deep sea air mixtures contain no more than 16% oxygen and oftentimes contain no nitrogen at all, substituting non-toxic gasses such as hydrogen and helium in their place.
Scuba Diving Equipment
A person in scuba diving equipment may look like a strange aquatic monstrosity to you, but every piece of that equipment is important to their survival underwater. From the tanks to the goggles, from the breath piece to the fins, the scuba suit is designed to help a human explore the underwater environments of our lakes and oceans.
If you think of scuba diving equipment the first thing you probably think of is the air tanks strapped to the back of a diver. These tanks contain compressed oxygen which is delivered to a diver via a supply line attached to a breathing piece. The simplistic looking system actually accounts for a complex difficulty inherent in trying to breathe underwater. As you descent, the outside pressure on your body increases, making it more difficult to breath. To offset this pressure, an air delivery system must supply you with air at the same pressure as the external forces acting on you.
In addition to the tank and mouthpiece, most scuba diving equipment sets include a wetsuit or dry suit, and fins for the feet. Wetsuits trap a layer of water next to your skin. Your body heat warms this water, which forms an insulating barrier against colder water you may dive into. A dry suit on the other hand forms a watertight barrier on the outside of the body. It keeps the entire covered area- usually everything but the head and hands dry. This allows excursions into much colder water than would otherwise be feasible.
Scuba gear is more than just your air tank and supply line. It includes things like your goggles, your wetsuit, your flippers, and technical equipment necessary for surviving underwater. It also includes any equipment used to conduct work or to play while underwater.
Some scuba gear, such as scuba fins or an underwater camera is non-essential. You will not die underwater without a camera. While you may find movement more difficult without fins on your feet, it again is a non life-threatening impediment. These non critical pieces of equipment are certain to make your life easier, but they are not necessary to attempt a dive.
Other pieces of scuba gear are absolutely essential. For instance going down without an air supply is a quick recipe for death. But the air supply is not the only thing you need. You need a proper delivery system that will give you the air at the right pressure for your body. You also need an air monitoring gauge to let you know how much air you have left. Wetsuits protect the body while underwater as well as helping you maintain a steady body temperature. Always check your gear to ensure that it is in good condition, the bottom of the ocean is no place to discover an equipment malfunction.
Scuba masks come in two major categories, partial or traditional masks only cover the eyes and nose; full facial masks cover the entire front of your head, from forehead to chin. The major purpose of a diving mask is to allow the diver to see underwater.
Scuba masks are required for us to see underwater because of the way water transmits light. Water has a higher refraction rate than air does; this means water scatters light more readily than air. This is why you can see much further on a clear day than you can when it is raining; the water scatters what light there is, reducing your vision. When water is in direct contact with your eye, it acts like a giant cornea, which distorts everything you see. Diving masks compensate for this by allowing the light to enter your eye from the small space of air in the mask instead of from the water directly.
While this allows you to see more clearly than you otherwise could, you still have distorted vision while underwater. The majority of advances in scuba masks have gone into reducing the distortion inherent in underwater vision. The most modern masks use a dual lens system- along with special contacts- to almost eliminate the distortion. The latest state of the art scuba masks can display diving information from your diving computer, such as depth, air remaining, temperature, and other useful information right on the surface of the mask.
Scuba travel can be taken to mean a few things. One is actually traveling places underwater with the aid of scuba equipment. The other is destination travel with scuba diving in mind. The underwater variety of scuba travel is limited by the technological and physiological barriers of humanity.
While we don’t ordinarily attempt to traverse distances of any great length underwater, there have been devices made to assist us towards that end. Sleds, or motorized propulsion devices allow an operator to move at speeds of two and a half knots or about ten miles per hour. While that may not seem all that fast; unaided humans move at less than three mph underwater. Even more importantly a person on an underwater propulsion device is not exerting themselves, allowing them to conserve air.
The destination variety of scuba travel involves flying to the location of a well known marine attraction, such as the Great Barrier Reef of Australia, or the Hawaiian Islands. These destinations have a robust scuba community including many guided scuba tours that allow a novice diver to experience some wonderful and unforgettable scenery.
Scuba fins are large fins attached to your feet. They help you propel yourself while under water. They are needed because human feet are not well suited to providing underwater thrust, especially when coupled with the additional drag created by the extra gear scuba divers invariable carry with them.
The term scuba fin is also known as a flipper. This is a more specific term, since a fin can include anything from the spoiler of a car to the tail of an airplane. The fins are usually made from flexible plastic, and come in many varieties. For instance some swimmers use mono-fins which are a single piece of plastic that fits onto both feet. This design allows the best thrust per leg movement ratio.
Other variations of the scuba fin include the split fin, the jet fin, and the force fin. Split fins, as the name implies, have a split trailing edge. This split acts somewhat like a propeller, enhancing each kick as it is made. Jet fins have vents cut into the fin to reduce drag and increase thrust. Force fins have an arching shape that recoils at each apex of a divers kick, adding additional force. They also have streamlined trailing edges making them more aqua-dynamic.
Scuba accessories are a category that includes anything non-essential to the dive being performed. Essential diving equipment includes a wetsuit or dry suit, flippers, a face mask, and an air supply & delivery system. Accessories cover pretty much everything else, from gloves, gauges, and diving computers to lights knives, and utility belts.
Dive computers are a new addition to the scuba accessory repertoire, but one with great potential. With a computer program monitoring your air supply, pressure, depth, and temperature you can spend more time in the water doing the things you want to. Some diving computers can even monitor your heart rate, download topographical maps, and keep track of compass heading and GPS information.
Other scuba accessories are situation specific. Knives are always handy, but how many knife blades are made to resist the corrosion of salt water? There are specifically forged diving knives to do just that. How about a water resistant flashlight to check out that cool looking cave? You bet- some lights have depth ratings of over 1000 feet!
Scuba Dive Gear
Your scuba dive gear is important to your underwater safety. The most comprehensive piece of dive gear is your wetsuit. The wetsuit controls your body temperature to keep it from dropping too far in cold water conditions. Less well known but equally important is the fact that your wetsuit is abrasion resistant. You don’t want to get cut on that coral reef after all… there may be sharks around.
Another important yet obscure piece of scuba dive gear is your monitor. This apparatus is attached to your air supply and will monitor your usage, as well as reserve supply to estimate your remaining dive time. Sophisticated models can track other information, such as depth and estimated decompression stop times.
The all important tank makes another vital piece of scuba dive gear. Your tank should be checked for flaws or defects before each use. Always remember that it is your life on your back underwater, and treat it with care. Do not back into rocks or other sharp object that may puncture your tank, for that would be disastrous.
Scuba sets are complete gear packages ideal for the beginning scuba diver who may not know everything they need for an underwater excursion. While they may seem pricey at first glance, they include everything necessary for a successful dive.
It is important for you to know what you are getting into with a scuba set. So if you are not a licensed diver, it is important to become certified. Most states offer scuba certification classes. These classes will teach you the basics of scuba safety as well as how to properly equip a scuba set. They may also cover basic maintenance of your scuba gear.
Once you have a scuba set and proper training, it is a simple matter of arranging some dives. Most locations offer guided diving tours, although if you wish to simply rent a boat and go exploring that is also an option. Remember that if you are not on a guided tour, always let someone know that you are going out and were you will be. It’s also important to check the weather before diving, a severe storm is not just an inconvenience, it is dangerous!
Even if your state does not border the ocean, odds are you have scuba supply stores in your area. Scuba diving is an extremely popular hobby, with many people taking vacations specifically to dive. But regardless if you are a first timer or an old hand, a scuba store will have something for you.
Scuba stores will sell wetsuits, dry suits, air tanks, masks, air supply systems, and anything else you may need for diving. But more important than that is the staff. These stores are run by scuba enthusiasts who live their work. If you need advice on where or when to dive, they can assist you. Your local scuba store is a great resource to tap when learning a new area.
But more than that, if you need advice on what to purchase, or how to maintain your equipment these people can help. They have years of experience in scuba diving, and if you’re unsure about anything, they can walk you through how to do just about anything. If you need help adjusting your air tank to sit more comfortably, they can help. If you need to know what kind of diving computer is best for you, they are the ones to turn to. If you wonder whether your air supply system has been compromised, take it to them to look at.