Free Diving

Free-diving

Sponge diving is the oldest known form of the original art of underwater diving, in order to retrieve natural sponges for human use.

Spearfishing is an ancient method of fishing that has been used throughout the world for millennia. Early civilizations were familiar with the custom of spearing fish from rivers and streams using sharpened sticks.

Spearfishing may be done using free-diving, snorkeling, or scuba diving techniques. Spearfishing while using scuba equipment is illegal in some countries. The use of mechanically powered spear guns is also outlawed in some countries and jurisdictions. Spearfishing is highly selective, normally uses no bait and has no by-catch.

Free-diving  is a form of underwater diving that relies on a diver's ability to hold his or her breath until resurfacing rather than on the use of a breathing apparatus such as scuba gear. Examples include breath-hold spear fishing, free dive photography, recreational breath-hold diving, apnea competitions, and to some degree, snorkeling. The activity that garners the most public attention is the extreme sport of competitive apnea in which competitors attempt to attain great depths, times, or distances on a single breath.

Free divers

Who've trained their bodies and minds to function underwater for long periods without taking a breath.

As scientists have discovered, even though humans evolved on land, we've retained a trace of that reflex, too. Free divers have learned to push self-induced apnea -- the scientific term for going without breathing -- to new extremes through sophisticated mind-body control techniques similar to those employed by meditating yogis and martial artists.

History

People started diving into deep water and making like dolphins thousands of years ago, long before they understood exactly why they had the ability to do it. Ancient Greek divers weighted themselves down and descended to depths of 100 feet (30.5 meters) or more to pluck sponges from the sea bottom. In Japan and Korea, traditional female free divers known as Ama have long collected edible seaweed and clams at depths of 65 feet (19.8 meters) or more. Because coastal dwellers have been free diving for many generations, you might suspect that they've developed special genetic traits that make them better at it than inlanders. But scientists who've studied them say there's no evidence of that.

All humans do share an evolutionary adaptation with air-breathing aquatic animals that makes it possible for them to dive and swim underwater for a while without taking a breath. In 1870, French physiologist Paul Bert observed that ducks had an amazing ability to slow their heart rate if they were forced to stay underwater. Scientists went on to discover that immersion in cold water -- or even simply holding your breath -- triggers something called the diving reflex, which the body uses to conserve life-giving oxygen. When the reflex kicks in, your pulse slows and your circulatory system constricts, and blood is shunted away from your muscles, skin and visceral organs, guaranteeing that your heart and brain get first dibs.

For years, scientists believed that humans were capable of enduring without oxygen for only a few minutes and that they couldn't dive deeper than 164 feet (50 meters), because the pressure would shrink their lungs and crush their rib cages. But in the 1960s and 1970s, divers disproved that myth. As it turns out, a phenomenon called blood shift causes the lungs to fill with plasma, preventing collapse.

In 1976, French diver Jacques Mayol became the first human to descend to (328 feet) 100 meters. Mayol, who studied Indian yoga and the breathing techniques of kung fu-practicing Shaolin monks, adapted those mind-body control methods to slow his pulse from 60 to 27 beats per minute underwater, enabling him to dive deeper and longer. In doing so, he revolutionized free diving and paved the way for Herbert Nitsch's generation of divers to push the limits even further.

Even then, tragedies sometimes occur. In 2002, elite French diver Audrey Mestre was attempting to set a no-limits depth record off the coast of the Dominican Republic, when equipment malfunctions apparently kept her underwater too long. She lost consciousness during her ascent and perished. Another French champion free diver, Loic Leferme, died off the south of France in 2007 when his ascent rope became snagged.

Now days free diving is a technique used with various aquatic activities. Examples of recognized free diving activities are (non-) competitive free diving, (non-) competitive spearfishing, free diving photography and mermaid shows. Less recognized examples of free diving include, but are not limited to, synchronized swimming, underwater rugby, underwater hockey, underwater hunting other than spearfishing, underwater target shooting and snorkeling. The discussion remains whether free diving is only a synonym for breath-hold diving or whether it describes a specific group of underwater activities. The term 'free diving' is often associated with competitive breath-hold diving or competitive apnea.

Physiology

The human body has several reflex oxygen-conserving adaptations that manifest under diving conditions. The adaptations include:

Reflex bradycardia: Drop in heart rate.

Splenic contraction: Releasing red blood cells carrying oxygen.

Blood-shift: Blood flow and volume is redistributed towards vital organs by means of a reflex vasoconstriction. Blood vessels distend and become engorged, which in the case of the pulmonary capillaries assists with pressure compensation that comes with increasing diving depth, and without which a largely air-filled chest cavity would simply collapse for lack of compliance.

Body-cooling: peripheral vasoconstriction results in cooling of peripheral tissue beds, which lower their oxygen demand in a thermodynamic manner. In addition, Murat et al. (2013) recently discovered that breath-holding results in prompt and substantial brain cooling, just like in diving birds and seals. (Dry) breath-holds result in cooling on the order of about 1°C/minute, but this is likely to be greater with cold water submersion, in proportion to the magnitude and promptness of the dive response.

Techniques

Tips:

• Bigger fins are harder to handle but have better results (more power/faster)
• You will need to equalize once you get to about 3 meters below the surface. Do this by pinching your nose shut and trying to exhale through your nose. You will need to do this regularly, especially in the first meters where the pressure changes a lot. Your inner ear will equalize automatically on your ascent.
• DO NOT dive deeply if you have a cold or are unable to equalize, you may do serious damage to your ear drums.

Steps are:

• Time your breath-holding capacity underwater, and record it for future reference.
• Take your pulse rate by putting both your index and middle finger together and either hold on your wrist or side of neck. You only need to apply slight pressure and wait a few seconds to feel slight "pumps" count for two minutes. Divide this by 2 (makes for a more accurate pulse rate) and you should now have your pulse rate. Record this and keep track of it.
• Figure out how far down you can go on one breath, but do it with a partner in case of blackout. Record this depth.
• Practice taking slow, deep breaths -5 seconds on the inhale - and 10-15 seconds or more on the exhale. (WARNING: If you keep the same timing for inhale and exhale, you'll do hyperventilation. This may lead you to blackout). After you've mastered this, remain still and do it while having somebody else record your pulse.
• Practice this until you can hold a pulse of under 80 beats a minute before starting the next step.
• Try going down after deep breathing at the same location you did your last dive. If you went down 7-10 feet the first time, try to get it to 16 feet, 11-19 feet try to go to 25 feet, 30+ just try to beat it by ten feet.
• Try practicing the above steps over and over. Your pulse should get to 60 or below after about a month, so try getting fins and testing how far you can go.
• Practice slow, deep, refined kicks with the biggest fins you can find and you will descend faster with fins later on. (Get proper free-diving fins with a soft action)
• Try spending 1 minute under water and 1 minute out of the water to let the co2 escape from your lungs.
• Grab a rock to help prevent your body's natural buoyancy.

Warning

• Do not hyperventilate. Hyperventilating before your dive will expel and decrease the amount of CO2 in your system. CO2 levels in your blood are what triggers your senses to exhale and take in another breath when you hold it. Therefore, removing CO2 only prolongs the period before the body needs to inhale. Hyperventilation does not increase the amount of oxygen present in the body. While you may be able to hold your breath longer at depth, you will be more prone to blackout on the ascent.
• When diving deeply (below 20') your lungs compress enough that re-surfacing may be harder than expected.
• Never dive at night or in a strong current area. Currents get significantly stronger farther down.
• Do not attempt if you have heart or lung problems.
• Never take medication to clear your sinus, as the mucus could come back and make it difficult to equalize when ascending
• Never dive unless you are with someone who could rescue you from the depths you'll be going to.

Equipment

Fins,
Carbon Fins
Fiberglass Fins






Monofins.







Blades,
Carbon Blades
Fiberglass Blades



Masks








Snorkels

Wetsuits & Swimwear.

Disciplines

Competitive free diving is currently governed by two world associations: AIDA International (International Association for Development of Apnea) and CMAS (World Underwater Federation).

Pool disciplines

Dynamic with Fins (DYN) the free diver travels in a horizontal position under water attempting to cover the greatest possible distance. Any propulsion aids other than fins or a monofin and swimming movements with the arms are prohibited Dynamic with fins is the most typical of both disciplines measuring the distance in free diving, because of the specific means of propulsion : long fins or monofin. Performances could only be recognized in swimming-pools with a minimum length of 25 meters, and are sometimes considered in national or indoors 'combine', with the Static apnea.

Dynamic without Fins (DNF) the free diver travels in a horizontal position under water attempting to cover the greatest possible distance. Any propulsion aids are prohibited. Dynamic without fins is the most natural of both disciplines measuring the distance for many free divers, because it doesn't need any propulsing material, but a very good technique. Performances also could only be recognized in pools with a minimum length of 25 meters, and are greatly appreciated from "old-swimmers".

Static Apnea (STA) the free diver holds his breath for as long as possible with his respiratory tracts immerged, his body either in the water or at the surface. Static apnea is the only discipline measuring the duration, and one of the three disciplines considered for the international competitions by team, with Constant weight and Dynamic with fins. Performances could be done and recognized in both pool and open water (sea, lake, river, etc.)

Depth disciplines

No Limit (NLT) The free diver descends with the help of a ballast weight and ascends via a method of his choice. No limit is the absolute depth discipline. Going down with a sled, and going back up with a balloon, a diving suit or a vest with inflatable compartments, or whatever other means.   

Variable Weight (VWT) The free diver descends with the help of a ballast weight and ascends using his own strength: arms and/or legs, either by pulling or not pulling on the rope. Variable weight is the first of both depth disciplines using a sled to go down in the water. Old sleds was descending "head first", like presented in the famous Luc Besson's movie "Le Grand Bleu", but new sleds descending "feet first" are now generalized.      
  

Constant Weight (CWT) The free diver descends and ascends using his fins/monofin and/or with the use of his arms without pulling on the rope or changing his ballast; only a single hold of the rope to stop the descent and start the ascent is allowed. Constant weight is the common sportive depth discipline of free diving, because of the specific fins or monofins used in it. Constant weight is one of the three disciplines considered for the international competitions by team, with Static apnea and Dynamic with fins.

Constant Weight without Fins (CNF) The free diver descends and ascends under water using only his own muscle strength, without the use of propulsion equipment and without pulling on the rope. Constant weight without fins is the most difficult sportive depth discipline, because of absolutely no propulsing material to go down in the water. This category needs a perfect coordination between propulsing movements, equalization, technique and buoyancy.   

Free Immersion (FIM) The free diver dives under water without the use of propulsion equipment, but only by pulling on the rope during descent and ascent. Free immersion is the sportive depth discipline with the purest sensations, because of the speed of the water in the body, and the power of each pull on the rope as only mean of propulsion. Performances could be done the head first during the descent, or the feet first, depending equalization facilities of each free divers... Some of them also even use mixed solutions.