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Diving

Specialty Definition: Diving

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Specialty Definition: Diving

(From Wikipedia, the free Encyclopedia)

Also see diving mammals and diving insects Diving has two meanings: jumping head-down into water, and swimming under water.

Diving in the first sense is the act of deliberately entering a body of water by jumping in, with arms pointed out stretched parallel with the straightened legs and torso, in an inverted position to minimise drag against the water. Competitive swimmers enter the water by diving from blocks above the ends of the pool.

Competitive diving involves performing dives into a pool off either springboards -- long, flexible planks that bend as the divers repeatedly jump on the end of the board to gain height and speed before diving, or rigid platforms of greater height. In elite competition, there are two springboard height competitions, one with the springboard at 1 metre above the pool surface, and one at 3 metres, and a platform competition at 10 metres.

Divers can perform a variety of different dives, performing somersaults and twists in various orientations and from different starting positions (including, from the platform, dives from a handstand starting position). Divers are judged on whether they completed all aspects of the dive, the conformance of their body to the requirements of the nominated dive, and the amount of splash created by their entry to the water (less being better). The raw score is then multiplied by a difficulty factor, dives containing more movements rating higher difficulty factors than dives with less. The diver with the highest total score after a sequence of dives (usually eight in elite competition) is declared the winner.

While not a particularly popular participant sport, diving is one of the more popular Olympic sports with spectators. Successful competitors possess many of the same characteristics as elite gymnasts, including strength, flexibility, and kinaesthetic judgment. Many world and Olympic diving champions are from China.

The Boys Own Book of Outdoor Sports adds:

Having now tolerably mastered the surface of the water, the learner must proceed to explore its depth. It is, of course, a great thing to be able to support the body in the water; but the swimmer's education is only half completed until he knows how to dive. Many lives have been saved by the ability to dive, many have been lost from its absence.

Many a man has saved his own life, when escaping from enemies, by diving and swimming under water to some place of refuge, or by passing along out of sight of his enemies, merely allowing his nostrils to appear above the surface at intervals. Many a man - and woman, too - has saved the life of another by diving after the sunken body and bringing it to the surface before life was extinct. Therefore, our counsel is, that the young swimmer learn to dive without delay.

The first object is to keep the eyes open while under the water. In order to do this, sink yourself well under the surface, hold your hand before your face, and try to look at it. Don't be afraid of water getting into the eyes. A chance drop of fresh water flirted into the eyes will make them smart, but you may keep your eyes open even in salt water as long as you like without the least irritation.

Some persons recommend that the first experiment be made with a basin of water, in which the head is to be plunged. We specially recommend that this should not be done, and that the first experiment should be made while bathing.

When the young swimmer has learned that he really can keep his eyes open under water, he should drop to the bed of the sea or river, where it is about four feet in depth, some white object - one of the well-known alabaster eggs used for deluding sitting hens is as good an object as can be found. Still, a lump of chalk, a thick gallipot, or anything of like nature, will do very well.

Now, try to stop and lift the egg, and you will find two results. The first is that the egg will look as large as a hat, and the second is, that you will find very great difficulty in getting to it.

Now, try another way of getting to the egg. Drop it as before, spring up as high as the waist, bend your body well forward, throw the feet in the air, and try to reach the egg, head foremost. At first you will find this rather difficult, but after a little practice, it will come easily enough. Be careful to stand at some little distance from the egg, or you will be sure to overshoot it.

Next drop the egg, go back some eight or ten yards, swim towards the object, and dive for the egg, from the swimming posture. This is not very easy at first on account of the difficulty in getting the chest below the surface. If, however, the legs are thrown well up in the air, the weight forces the body under water.

The next object is to try how far the swimmer can proceed under water.

Swimming under water is managed in nearly the same manner as swimming on the surface. But in order to counteract the continual tendency upwards, the swimmer must always keep his feet considerable higher than his head, so that each stroke serves to send him downwards as well as forwards.

One of the chief difficulties in diving is to keep a straight course, because there is seldom anything under water by which to steer. In a river, when the water is clear, it is generally easy to look upwards and watch the g\\trees, posts, or other objects on the banks; but in the sea it is very different business, and the swimmer must have learned to make his stroke with great regularity before he can dive in a straight line.

It is hardly possible to give too much time to diving. The learner should first take nothing but easy diving, such as have been mentioned, and then try to achieve more difficult feats. He should learn to dive at a considerable distance from any object, swim towards it by guess, and try to bring it towards the surface. He should throw two, three or more eggs into the water and try how many he can recover at a single dive. When he has attained a sufficient mastery over the water, he should stand on the bank, or in a boat, throw an egg into the water, dive after it, and catch it before it reaches the bottom.

This is a favorite feat of ours, and when we were yet in the jacketed state of humanity, we used to secure many a penny and occasional sixpences by thus diving after them, the copper coins being wrapped in white paper to make them more visible. Sixpences were easy enough to see, but not so easy to catch, because their flat form and light weight made them move backwards and forwards instead of descending steadily through the water.

The Header - Now the young swimmer must learn how to enter the water in a proper and graceful manner. It is as easy to enter the water gracefully as clumsily, and only requires a little care at first.

Most beginners are dreadfully alarmed when they are told to jump into the water first. They cannot rid themselves of the instinctive idea that their heads will be dashed to pieces. Consequently, when they try the "header" they only come flat on the water with a flop, and a great splash, and hurt themselves considerably, the blow against the water having almost as stinging an effect as a stroke from a birch rod.

Therefore, let not the beginner try too much at first. He should go to the bank of a river where the water is only a few inches below him, and there make his first attempt at a header. He should stoop down until he is nearly double, put his hands together over his head, lean over until they nearly touch the surface, and so quietly glide, rather than fall, into the water. At first he will be sure to lose the proper attitude, but in a little time he will manage without difficulty. This should be done over and over again, and each time from an increased height.

Next, the leaner should take a short run, and leap head first into the water from the place where he took his first lesson at plunging, so that the water is no great distance from him.

He should then remain quite stiff, straight, and still, and see how far his impetus will carry him. This is technically termed "shooting." At last he should accustom himself to leap from a considerable height, say from ten to twenty feet, and to do so either running or standing.

It is our firm belief that when the young swimmer has once ventured to jump from a height of ten feet, he will not be in the last alarmed at thirty or forty feet. At first there is a curious sensation as if all the internal machinery of the body were left in the air, the feeling very soon goes off, and the diver quite enjoys the rapid rush through the air. The oddest thing is, that he does not seem to be falling, but the water seems to rise up and meet him.

Also, he should practice leaping into the water at a distance from the bank, and also should try to leap over obstacles, such as reeds, branches, or similar obstructions. Very good practice may be gained by fixing a couple of upright sticks in the ground close to the bank, tying a string across them, and going head-foremost over it. Of course, the string should be set low at first, and its height increased by degrees. The height over which an experienced person can leap is really astonishing. The great difficulty is to avoid catching the string with the knee, and this brings us to an axiom in all diving from a height.

Keep the body, arms, and legs perfectly stiff, and all in the same right line.

Any one who will do this can leap from extraordinary heights without the least fear of danger. The hands, joined over the head, form a kind of wedge, which cuts its way into the water and opens a passage into which the body passes. The head is so bent over the chest, that even the slight shock which ensues when the water is reached only effects the crown of the head, which is the part which is best able to bear it.

Those who wish to see the attitude of the body in perfection, cannot do better than watch the ex-champion of England, Mr. Beckwith, while performing his well-known series of aquatic feats. As he passes through the air from the elevated leaping-board, his body and limbs become as straight as a dart, and as stiff as if he were a statue carved out of wood.

When he reaches the water, there is not the least alteration of attitude, and he shoots through the water like a fish, traversing a wonderful space by the impetus of a single spring.

In jumping from a boat, the best way is to go to the stern and leap over, as there is no more resistance to the feet than is obtained by leaping over the side; and in getting into the boat again, always come to the stern, never in the side. Swim towards the boat with the feet high. Grasp the stern in both hands and kick the feet on the surface of the water, so as to keep them up; otherwise, the legs will be sucked under the boat.

Then give a vigorous kick with the feet and spring with the hands, and you will be lying on your breast over the stern, and to crawl fairly into the boat is then easy enough.

See also scuba diving, snorkeling, free diving

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Diving."

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Diving at the 1904 Summer Olympics

(From Wikipedia, the free Encyclopedia)

At the 1904 Summer Olympics, two diving events were contested.

Platform, Men

Pos	Athlete
1	George Sheldon (USA)
2	Georg Hoffmann (GER)
3	Frank Kehoe (USA)
3	Alfred Braunschweiger (GER)

Plunge for Distance, Men

Pos	Athlete
1	William Dickey (USA)
2	Edgar Adams (USA)
3	Leo Goodwin (USA)

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Diving at the 1904 Summer Olympics."

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Diving duck

(From Wikipedia, the free Encyclopedia)

Diving Ducks
Hardhead
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Aves Order: Anseriformes Family: Anatidae Subfamily†: Anatinae
Genera Marmaronetta Netta Aythya Rhodonessa
† See also dabbling duck perching duck

The 16 species of diving duck, also known as pochards, make up a sub-group of the biological subfamily Anatinae, which itself is part of the diverse and very large duck, goose and swan family, Anatidae. The latter article should be referred to for an overview of this very large family of birds.

Although the group is cosmopolitan, most members are native to the northern hemisphere, and it includes several of the most familiar northern hemisphere ducks.

This group of ducks is so named because its members feed mainly by diving, although in fact the Netta species are reluctant to dive, and feed more like dabbling ducks.

These are gregarious ducks, mainly found on fresh water or on estuaries, though the Greater Scaup becomes marine during the northern winter. They are strong fliers; their broad, blunt-tipped wings require faster wing-beats than those of many ducks and they take off with some difficulty. Northern species tend to be highly migratory; southern species do not migrate but the Hardhead travels long distances on an irregular basis in response to rainfall. Diving ducks do not walk as well on land as the dabbling ducks.

The diving ducks, together with the dabbling ducks and perching ducks make up the sub-family Anatinae.

The Marbled Duck (Marmaronetta angustirostris) is difficult to classify, but is often also placed in the diving duck group.

Family Anatidae

• Subfamily Dendrocygninae: whistling ducks
• Subfamily Oxyurinae: stiff-tail ducks and Freckled Duck
• Subfamily Anserinae: geese and swans
• Subfamily Tadorninae: shelducks, sheldgeese and steamer-ducks
• Subfamily Merginae: eiders, scoters, sawbills and other sea-ducks.

Male Hardhead.
Larger version

• Subfamily Anatinae: perching, diving, and dabbling ducks
  • diving ducks
    • Marbled Duck Marmaronetta angustirostris
    • Pink-headed Duck Rhodonessa caryophyllacea (extinct)
    • Red-crested Pochard Netta rufina
    • Southern Pochard Netta erythrophthalma
    • Rosybill Netta peposaca
    • Canvasback Aythya valisineria
    • Pochard Aythya ferina
    • Redhead Aythya americana
    • Ring-necked Duck Aythya collaris
    • Hardhead Aythya australis
    • Baer's Pochard Aythya baeri
    • Ferruginous Duck Aythya nyroca
    • Madagascar Pochard Aythya innotata
    • New Zealand Scaup Aythya novaeseelandiae
    • Tufted Duck Aythya fuligula
    • Greater Scaup Aythya marila
    • Lesser Scaup Aythya affinis
  • perching ducks
  • dabbling ducks

    Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Diving duck."

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Scuba diving

(From Wikipedia, the free Encyclopedia)

SCUBA is an acronym for Self Contained Underwater Breathing Apparatus. In short, scuba diving is an underwater activity practiced with the help of a system or an apparatus (usually a tank and air pressure regulator) able to provide a reserve of gas (usually air) in order to allow the diver to breathe air during the immersion.

CAUTION: USE Wikipedia AT YOUR OWN RISK

History

See also Timeline of underwater technology.

The first known use of air tanks is in Italy, 15th century: Leonardo da Vinci affirmed in his Atlantic Codex (Biblioteca Ambrosiana, Milan) that systems were used at that time to artificially breathe under water, but he did not explain them in detail due to what he described as "bad human nature", that would have taken advantage of this technique to sink ships and even commit murders. Some drawings, however, showed different kinds of snorkels and an air tank (to be carried on the breast) that presumably should have no external connections. Other drawings showed a complete immersion kit, with a plunger suit which included a sort of mask with a box for air. The project was so detailed that it included a urine collector, too.

After Leonardo's studies, and those of Halley (yes, the astronomer), in the 19th century August Siebe invented a sort of apparatus but still not completely independent of external air. His studies were perfected by the Frenchman Joseph Cabirol and later, more incisively, by Benoit Rouquayrol and Auguste Denayrouze, who added the first modern air tank.

In 1906 the first decompression tables ("quote decompression method") were released.

In 1915 Sir Robert Davis invented the "Submarine escape apparatus", by which a compressed oxygen bottle could be opened in water in case of need, sending air to mouth. Used air could be then expelled to a filtering "false lung" from where it is finally lost.

In 1925 Yves Le Prieur invented another better developed apparatus in 1933, working with compressed air. It could permit a 20 minute stay at -7 meters and 15 minutes at -15 (these data appear however to be re-checked).

In 1941, during WWII, these experimental apparatuses were used for one of the best known and most spectacular war actions: Italian "Decima Mas" (elite navy corps at the orders of commander Junio Valerio Borghese) entered at nighttime the port of Alexandria, Egypt, in immersion. They used special underwater vehicles ("maiali" = pigs) and breathing apparatus, and were able to silently attach miness on the bottom of the ships, that later were effectively sunk.

In July of 1943 the Frenchman Georges Comheines was able to reach -53 meters (~174 feet), off the coast of Marseille, with a two-bottles apparatus he had developed from Le Prieur's one. Immersion lasted 2 minutes (apparently out of decompression tables).

In the following October, Frédéric Dumas reached -62 meters (~200 feet), with the apparatus co-invented by Jacques Cousteau and Emile Gagnan and named Aqua-lung.

In 1958 the TV series SEA HUNT, introduced SCUBA diving to the TV audience.

Movies have also popularized the sport. SCUBA diving is featured in many James Bond films.

Nitrogen Narcosis Information

The maximum safe depth for normal scuba gear with normal air in the tank is certainly within 50 meters (~150 feet), beyond which nitrogen narcosis becomes an almost certain danger. Onset of narcosis is dependent on the workload, the physical conditions, and training of the diver but also depends on variable gas concentration in blood and lungs, that might change very suddenly with minimum changes of vertical speed (descent). Risk factors are different for each individual, and cannot therefore be reliably foreseen: the appearance of narcosis can be very rapid and faster than the capability of the diver to recognize it. Narcosis will also disappear once you ascend to shallower depth.

It is vital to remember that an accident can occur even in the very first meter of immersion, depending on personal conditions and hazards; every statistical report about accidents demonstrate that claimed "safe ranges" are nothing more than a rough recording of some data (episodically and not organically collected) with no scientific confirmation.

Diving can be an experience capable of producing unique emotions, but only with complete respect of safety rules. Any accident in water, even the "lightest" one, can bring to death to the untrained diver. The rising numbers of deaths in the early years of scuba forced training organisations of come up with minimum standards of training.

Some say that it could be possible to learn how to tolerate narcosis (allegedly, same as with alcohol), but disconcerting doubts cannot allow this statement to be released so easily without at least the mention that nothing and no one can seriously ensure that you will be able to reach again the surface if a similar accident happens, effective known rescues generally having depended on highly hazardous and quite randomized factors.

If Enriched Air Nitrox is used, additional serious risks come from oxygen toxicity. Diving on pure oxygen becomes toxic at a depth of merely 10 ft. Breathing mixes become dangerous when the partial pressure of oxygen reaches 1,4-1,6 bar. Some people consider 1,2 bar dangerous pressure (and some others suggest never passing 0,9), that is reached at a very early depth.

Relatively "safe" deep dives over 70 meters (~210 feet) can be done by well experienced divers using Heliox or Trimix gas mixes. As with Enriched Air Nitrox, special training is obligatory. These depths are however in a range that could recommend a boat-assisted immersion for a different air provision system, such as pneumatic pumps on surface.

Scuba diving requires training, and nobody should consider attempting to dive without professional instruction. Even experienced divers should never dive alone, but instead have a companion (or more) in sight.

Major deadly risk factors include:

• Vertical speed (descent and ascent)
• Lung problems i.e. (holding one's breath upon ascent which will cause your lungs to explode just as an overfilled balloon)
• Running out of air (often due to secondary factors such as getting trapped by nets, rocks inside caves, etc).

Major diving diseases include:

• Subcutaneous emphysema (gas under the skin tissue)
• Nitrogen narcosis ('Rapture of the Deep')
• Tympanum damage (damage to the eardrum caused by failing to equalize pressure in the inner ear).
• Decompression sickness

"Decompression sickness" ("the bends") is caused by ascending from deep depths too quickly. Nitrogen from the air breathed dissolves in the blood at depth, and as the diver ascends, the nitrogen is released from the blood and forms bubbles throughout the diver's bloodstream, with painful and often fatal results. The prevention is to surface slowly from all dives, so that nitrogen can "de-gass" from the diver's blood without forming bubbles. Divers also ensure adequate de-gassing by performing one or more "safety stops" after long or deep dives, in which the diver hovers at a prescribed depth for a prescribed amount of time before actually surfacing. Dive Tables (and dive computers which use the tables) are used to calculate maximum bottom time, and recommend additional safety stops.

Things to do underwater

• Relax and watch the marine life
  • fish watching
  • coral reef watching
  • feeding the fish (this has become controversial in recent years)
  • look for sunken treasure
  • hunt for food (spearfishing) (spear gun)
• Drift diving
  • Allowing the water current to move the diver down current, this is one of the most relaxing methods to dive.
  • Typically done in rivers or the ocean
  • Example - in Cozumel the boat takes the divers toward the south end on the island, the current runs from south to north, the divers exit the boat and drift north, the boat follows the trail of bubbles from the divers, when the divers surface the boat is waiting for them.
• Wreck diving
  • Viewing shipwreck or aircraft underwater
  • Requires special training to enter & exit a shipwreck Penetration diving
• Search & Recovery diving
  • Searching for an object using a pattern.
    • The size of the object and the visibility of the water help determine what pattern will be use.
  • After finding the object, returning it to the surface. Small objects can be carried up to the surface by the diver, larger objects may require the use of a lift bag.
    • Salvaging item from historical ship wrecks will land you in legal problems or jail
    • Mel Fisher is one of the best know treasure hunters
• Underwater photography
  • Capturing the underwater beauty can be one of the most challenging and rewarding efforts of scuba diving.
  • The current trend is a housed digital camera
  • Nikon - Nikonos V underwater camera (http://www.nikonusa.com/usa_group/group.jsp?cat=1&grp=7 )
  • SEA&SEA (http://www.seaandsea.com/ )
  • Nextus housings for camera's (http://www.nexusamerica.com/products.html )
• Underwater videography
  • Using a film / video camera underwater
• Marine life identification
  • Identifying & recording marine life seen in a given area
    • done as part of a survey or study
    • done for personal pleasure like bird watching
• Ice diving
  • Requires special training to dive under the ice on a body of water
  • Instruction by a certified instructor - typically one day
  • Requires additional scuba equipment
    • A regulator modified for cold water use that will not freeze.
    • A harness
    • A safety rope attached to the harness
    • Typically a dry suit is worn to keep the diver warm
    • A hood to keep the divers head warm.
      • Optional full face mask to prevent cold water from contacting the divers face.
  • Requires additional personal
    • Line Tenders to manage the ropes
    • Safety diver
    • Divemaster
  • Requires additional equipment
    • A weatherproof area for the divers to suit up
  • Requires additional equipment to access the water below the ice
    • A chain saw to cut the ice
    • Snow shovel to clear the snow and ice from the area
• Cave diving
  • Requires special training to enter and safely exit a cave - prevent your own death - do not enter a cave unless you and your buddy are trained cave divers.
    • Sheck Exley is a well known cave diver.
• Boat diving
  • Diving from a boat
  • Boats can range in size from a one man kayak to an ocean liner.
  • Many of the best diving sites are off shore and the boat provides access to these sites.
    • Six pack is a slang term for a small boat that can carry up to six divers.
      • Typically very fast boat with twin outboard engines
    • "Cattle boat" a slang term for a large boat that take a large group of divers
• Night diving
  • Diving after sunset & before dawn reveals new animals that come out at night and corals that open at night to feed. Many divers enjoy this more than diving during the daylight.
  • Requires a primary and back-up light source. Typically water proof flashlights designed for scuba diving. Additionally scuba diver wear marker lights to help locate and identify them. Cylume Sticks were popular but environmental concerns as phasing them out in favor of battery powered glow sticks.
  • While night diving divers tend to move slower and more deliberately than during the day light. This leads to a more relaxing dive.
• Altitude diving.
  • Diving in a body of water located above 1000 feet above sea level. Requires additional training and modified dive tables. Diver must limit the ascent rate to 30 feet pr minute or less.
  • Lake Tahoe would be an example of a location where altitude diving is done.
• Dive propulsion vehicle - DPV
  • Driving an underwater propulsion vehicle
  • Care must be taken not to assend to fast while driving the vehicle
  • Vechiles range in size from small unit to mulit passanger units
• Dry suit diving
  • A dry suit is a suit worn by scuba divers to keep water away from the diver's body. It is typically worn in water too cold for a wetsuit. Unlike a wetsuit, which traps a thin layer of water between the body and the suit, a dry suit has a neck and wrist seal to prevent water from entering, and the feet are usually enclosed. Divers add air to the suit to keep it from squeezing too tight on the body. In order to keep warm, dry suit wearers use either special underclothes or an electrical heating system.
  • Vulcanized rubber suit
  • Compressed neoprene suit
  • Shell suit
    • Trilaminate - Nylon/Butyl Rubber/Nylon
      • this type of suit offers no thermal protection, they divers wears undergarments for thermal protection.
      • offered in many colors
      • offered with self donning zipper than goes across the front of the suit, allows the wearer of the suit to close the zipper himself.
  • Zipper
    • the waterproof zipper is a product of the space age
    • some suits have a zipper across the back of the shoulders
  • Seals
    • Latex neck & wrist seals
      • can be trimmed to fit the owner of the suit, Latex seals are more delicate than neoprene and require more care.
    • Neoprene neck & wrist seals
      • can be trimmed if needed, neoprene seals will leak a little.
  • Inflator valve on chest to add air to the suit
  • Dump valve on left arm
    • automatically dumps air to prevent overinflation, this setting can be adjusted by the diver by rotating the top of the valve.
  • Manufacturers' web sites:
    • DUI (http://www.dui-online.com/newsite/newsite.htm )
    • Viking (http://www.geocities.com/CapeCanaveral/Lab/3518/DH-Viking.htm )
    • Gates (http://www.hunterboots.com/diving/ )
    • USIA (http://www.usia.com/ )
• Underwater navigation
  • using a compass and other item to find your way around underwater
  • GPS will not work underwater, the wavelenght will not penetrate the water.
• Communicating
  • Sign language: In most situations cummunications is facilitated with the use of simple hand signals. The most basic ones: Thumbs up = lets go up, thumbs down = lets go down, circle with thumb and index finger = I'm OK. Are you OK?, "cutting" throat with a flat hand = I'm out of air, wobbling a flat hand = something is wrong.
  • Using a torch/flashlight: The focused beam of a torch can be used for basic signalling as well. Drawing a circle on the ground in front of buddy = the OK signal, waving the torch = attention please!
  • Voice: When using special equipment, voice can be used for communication. Equipment usually consists of a full face mask with a submergible microphone and speaker and either a hard wired telepone-like setup or a through-water supersonic radio-like system.
• NITROX diving
  • Diving with a mixture of air with the nitrogen/oxygen ratio different than ambient air during a dive.
  • Using nitrox is typically not the purpose of the dive but nitrox is used during the dive
• Deep diving
  • diving below 100 feet / 30 meters.
  • 130 feet is the max depth for recreational scuba
• Rebreather
  • a device which reuses part of each breath. See linked article for more information.

Scuba Glossary

; Skin: a lycra suit worn by a diver in warm water or under a wet suit. ; Surface interval: the time between dives. divers need to track this time interval for planning the next dive. ; Time to fly: Divers must wait approx. 24 hours after the last dive before flying. ; Wall diving : Scuba diving along the face of a vertical wall ; Shore diving: Scuba diving that starts from the shore line ; Buddy System: Two divers that dive together as a team for safety ; Trash dive: a dive dedicated to removing trash from the underwater environment ; Divemaster: A professional level diver who is in charge of the dive. ; Beach master: A person on the beach who records when divers enter and exit the water. Typically used during scuba classes to keep track of the students, watch the gear, provide assistance when required. ; C-card: Certification card (proof of training or experience) ; Log Book: List of the dives a diver has recorded for proof of experience. ; Dive Tables: Give the maximum times that can be spent at depth, and pauses needed during ascent, before Decompression sickness becomes a danger. ; Navy Tables : A set of dive tables developed by the US Navy. Used by early divers as a method to determine maximum time and depth. ; Dive Shop : supplier of dive equipment or training, or organizer of dive expeditions. ; Dive Flag : Flag used by a boat to indicate that it has 'divers down'. Comes in two versions: the international (international code letter flag 'A', ) and the American (red flag with white diagonal, ), introduced by Ted Nixon in 1956. Boats must maintain a minimum distance away from the flag. Personal water craft pose a hazard to divers, and sadly few operators do know what a dive flag is. Some believe it is turn marker. If you observe a personal water craft operating to close to a dive flag contact the lake patrol. ; Hard Hat diving: A term for commercial divers. Refers to the old style brass helmet tethered divers used to wear. ; Dive club: a group of people with an interest in SCUBA diving ; Navy SEAL: A highly trained military diver (http://www.sealchallenge.navy.mil/ ) ; Frogman: A slag term for scuba divers ; Fire Diving: An urban legend about a diver who is scooped up by a plane/chopper and dropped on a forest fire led someone to build a web site for the fictitious sport of Firediving

Training and Certification

Becoming a scuba diver requires training. Dive training organisations can be found throughout the world, and in very large numbers in popular dive spots. A good dive training organisation will always offer courses to the standard of a recognised certification organisation, such as those listed below. Many dive shops in popular holiday locations offer courses that can teach you to dive in a few days, and can be combined with your vacation.

Initial training can be broken down into three phases.

• Classroom - where material is presented and reviewed
• Pool - where skills are taught and practiced in confined water
• Open Water - where the student demonstrates the skills he has learned. Typically done in a local body of water (lake, quarry, ocean)

Upon completing the course the student is issued a certification card.

Many of the activities mentioned above require additional training to be done safely.

Certifying dive organizations include:

• ACUC - American and Canadian Underwater Certifications (http://www.acuc.ca/ )
• BSAC - British Sub Aqua Club (http://www.bsac.com/ )
• CMAS - Confédération Mondiale des Activités Subaquatiques (http://www.cmas2000.org )
• GUE - Global Underwater Explorers (http://www.gue.com/ )
• IANTD - International Association of Nitrox and Technical Divers (http://www.iantd.com/ )
• IDEA - International Diving Educators Association
• NACD - National Association for Cave Diving (http://www.safecavediving.com/ )
• NAUI - National Association of Underwater Instructors (http://www.naui.org/ )
• PADI - Professional Association of Diving Instructors (http://www.padi.com/ )
• SSI - Scuba Schools International (http://www.ssiusa.com/ )
• YMCA - YMCA SCUBA (http://www.ymcascuba.org/ )

Other organizations:

• AAUS - American Academy of Underwater Sciences
• Active Divers Association
• ARSBC - Artificial Reef Society of British Columbia
• BFDC and North Carolina SCUBA/Wreck Diving
• Chicago Aquanauts Scuba Association
• DAN - Divers Alert Network
• GLACD - Greater Los Angeles Council of Divers
• HSA International
• Israeli Diving Federation
• Malta Professional Diving Schools Association
• National Association of Black Scuba Divers
• New York State Diver's Association
• MOAV - Mystic Order of Aquatic Vigilance
• NSS-CDS - National Speleological Society Cave Diving Section (http://www.nsscds.com/ )
• Odyssey Expeditions
• Recreational Divers Association
• Sub-Aqua Association
• USDDA - United States Dental Diving Association, Inc

Other: ACUC, ANIS, CEDIP, DIWA, ESA, FIAS, FIPS, IADS, IAHD, IDD, NASE, PDA, PSA, SUSV, TDI, TSA, VDST, VDTL, VIT, YMCA, ÖSPV

External links

• Scuba News,
• Divers Alert Network, founded in 1980
• SCBA Self Contained Breathing Apparatus

Popular locations for SCUBA diving

• Australia
  • Great Barrier Reef
  • Ningaloo Reef
• Cozumel, Mexico 20.5° N 86.9° W
• Red Sea, Egypt
• Caribbean Sea

Equipment Manufacturers

• Aqua Lung (http://www.aqualung.com/ )
• Body Glove Wetsuits (http://www.bodyglove.com/ )
• Dacor (http://www.divedacor.com/intro.html )
• Dite Rite (http://www.dive-rite.com/ )
• Dive Goddess Skins (http://www.divegoddess.com/ )
• Halcyon (http://www.halcyon.net/index.shtml )
• Henderson (http://hendersonusa.com/hendersonusa.html )
• Ikelite (http://www.ikelite.com/web_pages/1cat_index.html )
• Luxfer (http://www.luxfercylinders.com/products/scuba/ )
• Nikonos (http://www.nikonusa.com/usa_group/group.jsp?cat=1&grp=7 )
• OMS (http://www.omsdive.com/index.html )
• O'Neill Wetsuits (http://www.oneill.com/ )
• Poseidon (http://www.poseidon.se/ )
• Riffe International speargun (http://www.speargun.com/history.htm )
• Sea&Sea (http://www.seaandsea.com/ )
• Sherwood (http://www.sherwoodscuba.com/ )
• Torpedo DPV (http://www.torpedodpv.com/ )

Equipment used in scuba diving

• Mask
  • non purge
  • purge valve
  • single lens
  • split lens
  • full face - the diver in the first photo is wearing an AGA full face mask
  • other category
    • hard hat
• Fins
  • modern fins come in many shapes and colors
  • open heel type
    • 
• Snorkel
  • used by divers when swimming at the surface, worn on the left side of the mask.
  • some modern snorkels have drain valves to aid in the removal of water from the snorkel tube
• Weight Belt
  • A nylon web 2" wide that holds the weights and features a quick release buckle. Belts come in many color with yellow or black being the most popular.
• Weights - used to offset positive buoyancy.
  • Lead is the most common material used
  • 1, 2, 3, 4, or 5 pound blocks with holes to thread the weight belt through
  • Many modern BCD's have weight pockets with quick release buckles

A diver in a pool wearing a full face mask from AGA and a twin 6 liter 300 bar tank rig.

• SCUBA tank
  • A hollow cylinder that holds compressed air with an on/off valve at the top.
  • Typically filled to somewere the range of 18.6 to 30.0 MPa (2700 to 4300 psi)
  • Some countrie require a burst disk installed in the valve that prevents pressures exeeding approx. 15% above working pressure.
  • Tanks should only be filled with air from a reliable source (dive shop)
  • Never fill a tank with oxygen unless it has been certified for pure oxygen use.
  • Contaminated air at depth could be fatal
  • Common sizes - materials for scuba tanks
    • 80 cubic feet - Aluminum - most common size used
    • 63 cubic feet - Aluminum
    • 72 cubic feet - Steel
    • 50 cubic feet - Aluminum
    • 30 cubic feet - Aluminum "pony bottle"
    • 13 cubic feet - Aluminum "bailout bottle"
    • 100 cubic feet - Aluminum
    • 120 cubic feet - Steel
    • Twin 80's - Two 80's with a manifold that connects them. Twin tanks are typically used in technical diving.
    • Most counties requires tanks to be checked on a regular basis. This usually consists of an internal visual inspection and a hydrostatic test. In the United States, an visual inspection is required every year, and a hydrostatic every five years.

• Buoyancy Control Device BCD or BC
  • Modern BCDs are the jacket model that is worn like a vest. Looking a little like a lifejacket, they allow the diver to change his buoyancy while under water by adding or releasing air.
  • Low pressure inflator
    • a hose on the left side of the jacket that allows air to be added or released from the jacket. The inflator should be held higher than the jacket to release air.
  • Over pressurization valve
    • A spring loaded valve that prevents the jacket from holding too much air, can also be used to rapidly dump air from the jacket
• Backpack
  • Holds the tank in place
  • Modern Buoyancy Control Devices have the backpack built into the unit.
• Regulator
  • Attaches to the SCUBA tank, reduces the tank pressure to ambient pressure.

All modern regulators consists of two stages. The first stage attaches to the tank and reduces the tank pressure to aprox. 1 MPa obove ambient pressure. This intermediate pressure gas is lead through a hose to the second stage witch in turn reduces the gas pressure to ambient pressure.

• • Double hose style

Earlier models of regulators had the two stages combined into one. Air was supplied to the diver via a large corrugated hose to the divers mouth piece. Exhaled gas returned via a second hose back to the regulator where it was released into the water.

• Underwater Compass

Works just as the "dry" versions. Often worn on the forearm, just as a clock.

• Under Water Time Piece
  • Waterproof Watch to keep track of time
• Air pressure gauge
  • Used to monitor the tank pressure
  • Connects to the first stage of the regulator.
• Depth Gauge
  • Used to monitor depth
• Console
  • a plastic or rubber box that holds the air pressure gauge and the depth gauge, typically worn on the left hand side of the diver
• Dive Computer
  • Watertight computer with LCD display showing the amount of time the diver can remain underwater while staying inside decompression sickness safety limits
  • Most fit into the console or into a wrist mount
  • 

Movies that feature Scuba Diving

• The Abyss
• Thunderball James Bond
• Fantastic Voyage

Scuba Magazines

• Dive Training (http://www.dtmag.com/ )
• Aqualog Magazine - dedicated to the promotion of scuba diving and underwater worlds through articles from authors around the globe.
• California Diving News - articles, boat schedules, and dive buddy directory.
• Cyber Diver - offers daily news updates, objective scuba gear reviews, and unbiased dive travel reports.
• CyberSea Scuba Journal
• Deeper Blue - international independent online magazine for divers. Offers editorials, feature articles, tips, discussion forums, and more.
• Dive Girl - by women scuba divers, covering recreational and technical diving.
• Dive New Zealand - online magazine containing articles, photos, dive sites, news, and more.
• Dive-online.com - site of "Dive", the official magazine of BSAC.
• Diver Magazine - Canada diving magazine. Articles on dive travel, wreck diving, marine life, u/w photography, equipment reviews, and more.
• DiverNET - diving community site with news, scuba equipment reviews, holiday offers, listings and forums, weekend weather for divers, competitions, e-cards, and wreck tours.
• Florida Scuba News - listing of dive shops and dive boats as well as up-to-date information on diving in the Sunshine state
• Immersed - containing interesting ideas and dive sites for technical divers around the world.
• Northwest Dive News - offers a variety of information about diving in the Pacific Northwest.
• On-the-Edge - offers advertising and public relations services to the ocean sports industry.
• Philippine Diver - covers scuba diving and other watersports in the Philippines.
• Rodale's Scuba Diving Magazine - The Magazine Divers Trust is online with a worldwide dive travel index, equipment reviews, scuba training, dive medicine, marine biology and u/w photography.
• Skin Diver Magazine - over 1000 articles, new features every month, scuba search engine, buddies, clubs, events and more.
• South Florida Dive Journal
• Sport Diver Magazine - covers diving destinations, equipment, training, and more.
• Sportdiving Magazine - covers Australia and the Indo-Pacific regions. Includes online subscription form.
• Undercurrent - online scuba diving magazine providing reviews of dive resorts and scuba equipment.

  Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Scuba diving."

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Modern Usage: Diving

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Commercial Usage: Diving

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Image Slideshow: Diving

Photos: Diving More pictures...

Illustrations: Diving More pictures...

Computer Images: Diving More pictures...

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Photo Album: Diving

Thumbnail	Description & Credit	Thumbnail	Description & Credit
	A 9 year-old white child is shown here in a swimming pool and on a diving board with friends. Sheis a long-term survivor of massive abdominal surgery at age three for neuroblastoma. She is presently disease-free. Credit: Linda Bartlett (photographer).		Boy diving into swimming pool. Exercise, recreation. Credit: CDC.
	Hanauma Bay, southeast coast of Oahu. A popular bathing and diving beach. Credit: America's Coastlines.		A favorite diving spot at the City of Refuge. Credit: America's Coastlines.
	A diving killer whale in Frederick Sound. Credit: Paths Less Taken - NOAA at the Ends of the Earth.		"Penguins Diving." In: "Scott's Last Expedition ....", 1913. Dodd, Mead, and Company. New York. Volume II. Page 108. Credit: Paths Less Taken - NOAA at the Ends of the Earth.
	An early diving bell used by 16th Century divers during salvage operations. The book this came from is a text on ship salvage and includes diving information. In: Regola generale di soleuare ogni fondata naue & nauilii con ragione" by Niccolo Tartaglia. Credit: National Undersea Research Program (NURP).		DSV Alvin hovers above deck before diving to 4,000 meters. Credit: National Undersea Research Program (NURP).
	Truk native diving on artificial reef. Credit: The Coral Kingdom.		A hazard of a diving marine biologist. Hammers on the head tend to discourage attack. Carcharinis Limbatus - grey shark on a murky day at the reef. Credit: The Coral Kingdom.
Source: pictures compiled by the editor from various references; see picture credits.

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Digital Photo Gallery: Diving
 

"Puddle diving" by Max Gaugush Commentary: "A kid lands a perfect dive with a half twist into a puddle."	"No Diving" by Jeremy Lounds Commentary: "A homemade "no diving" sign for a shallow marsh near Lake Superior."
Source: photographs selected by the editor, with permission from the photographers.

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Familiar Quotations: Diving

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Non-Fiction Usage: Diving

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Usage Frequency: Diving

Source: compiled by the editor from several corpora; see credits.

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Expressions: Diving

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Frequency of Internet Keywords: Diving

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Modern Translation: Diving