Rafting

Rafting and white water rafting are recreational outdoor activities which use an inflatable raft to navigate a river or other body of water. This is often done on whitewater or different degrees of rough water, and generally represents a new and challenging environment for participants. Dealing with risk and the need for teamwork is often a part of the experience. The development of this activity as a leisure sport has become popular since the mid-1970s, evolving from individuals paddling 10 feet (3.0 m) rafts with double-bladed paddles to multi-person rafts propelled by single-bladed paddles and steered by a tour guide at the stern. It is considered an extreme sport, and can be fatal. The International Rafting Federation (IRF) is the worldwide body which oversees all aspects of the sport.

Classes of white water
Otherwise known as the International Scale of River Difficulty, below are the six grades of difficulty in white water rafting. They range from simple to very dangerous and potential death or serious injuries.

• Class 1: Very small rough areas, might require slight maneuvering. (Skill level: very basic)
• Class 2: Some rough water, maybe some rocks, might require some maneuvering. (Skill level: basic paddling skill)
• Class 3: Whitewater, small waves, maybe a small drop, but no considerable danger. May require significant maneuvering.
• Class 4: Whitewater, medium waves, maybe rocks, maybe a considerable drop, sharp maneuvers may be needed.
• Class 5: Whitewater, large waves, large volume, possibility of large rocks and hazards, possibility of a large drop, requires precise maneuvering.
• Class 6: Class 6 rapids are considered to be so dangerous that they are effectively unnavigable on a reliably safe basis. Rafters can expect to encounter substantial whitewater, huge waves, huge rocks and hazards, and/or substantial drops that will impart severe impacts beyond the structural capacities and impact ratings of almost all rafting equipment. Traversing a Class 6 rapid has a dramatically increased likelihood of ending in serious injury or death compared to lesser classes.

Techniques
Rafts in white water are very different vehicles than canoes or kayaks and have their own specific techniques to maneuver through whitewater obstacles. Examples of these techniques include.

Punching – Rafts carry great momentum, and on rivers hydraulics that are dodged by canoes and kayaks are often punched by rafts. This involves the rafting crew paddling the raft to give it enough speed to push through the hydraulic without getting stopped.
High siding – If a raft is caught in a hydraulic it will often quickly go sideways. In order to stop the raft flipping on its inside edge, the rafters can climb to the side of the raft furthest downstream, which will also be the side of the raft highest in the air leading to its name. In this position the rafters may be able to use the draw stroke to pull the raft out of the head.
Low siding- more of a proffessional manuever sometimes used at LOW water to slide through a channel less than the size of your craft.

Capsizing
Dump truck – Rafts are inherently stable crafts because of their size and low center of mass and often they will shed gear and passengers before they actually capsize. In the industry if a raft dumps some or all of its passengers but remains upright, it is said to have dump trucked.
Left over right or right over left – Rafts almost always flip side over side. If the left tube rises over the right tube, the raft is said to have flipped left over right and vice versa.
Taco – If a raft is soft, or under inflated, it may taco, or reverse taco. Rafts are said to have tacoed if the middle of the raft buckles and the front of the raft touches or nearly touches the back of the raft. This often is a result of surfing in a hydraulic. A reverse taco is when the nose, or stern of the raft is pulled down under water and buckles to touch the middle or back, or nose of the raft.
End over end – Occasionally rafts will flip end over end. This is usually after the raft has dump trucked to lighten the load, allowing the water to overcome the weight of the boat flipping it vertically before it lands upside down. Rafts will more often taco and turn sideways, making an end-over-end flip a very rare flip in most rafts.
Down Stream Flip- A raft capsizes after encountering an obstacle i.e. rock, feature like a hydraulic or even another raft. These objects are usually stationary or possibly surfing in a hydraulic. On this occasion the raft becomes unstable and usually flips over downstream or in the direction of travel. A downstream flip may be exacerbated by the load or people in the raft. People may physically assist in the inertia of the flip by pulling the boat over on top of themselves.
Back roller - A broad reversal such as that formed below a dam or ledge. Rafts can be particularly vulnerable to these, because they can quickly fill a raft and then push it down at the back. If there are snags at the bottom of the river, dumped rafters can be caught and drowned in the aerated and therefore less buoyant water.
Dark Sideing - To cilmb over a side tube as the craft flips. In swim beer rules, anyone to witniss one of these owes beer to the "successful flippie". he or she may be responsible for any beer owed for the ensuing clean up depending on region.

Re-righting
Flip line – The flip line technique is the most used in commercial rafting where flips are common. The guide will take a loop of webbing that has a biner on it and attach it to the perimeter line on the raft. Standing on top of the upside down raft they will hold the line and lean to the opposite side from where the flip line is attached, re-righting the raft.
Knee flipping – Capsized rafts that are small enough with little or no gear attached can be knee flipped. This involves the rafter holding the webbing on the underside of the raft, and pushing their knees into the outer tube, and then lifting their body out of the water, leaning back to overturn the raft.
T rescue – Somewhat like the kayak technique, some rafts are large enough that they need to be overturned with the assistance of another raft or land. Positioning the upturned raft or land at the side of the raft, the rafters can then re-right the raft by lifting up on the perimeter line.
T-grip re-flip - The T-grip on a rafting paddle may be used to re-flip light rafts by inserting the Tee into the self bailing holes around the floor perimeter and re-righting the boat in the same manner as the flip line technique.

Tricks
Rock splats – If the rafters load the back of the raft, they can paddle the raft into a rock on the river, having it hit the bottom of the boat instead of the nose; if done correctly this can raise the raft up vertically on its stern and possibly flip.
Pillow ride- Water will "pillow" as current hits a vertical surface. The craft can be pointed into this type of hydraulic,and with verying degerees of success can be driven smoothly up the vertical surface ,smoothly off the side and either into an eddy or into the current. This can be a dangerous maneuver as it can easily flip or dump a raft. This should never be done intentionally on strainers, undercuts, or above sieves. ALWAYS exercise caution, but have fun.
Surfing – Craft often use waves/ hydraulics on rivers to surf. Normally this is done by "eddying out" below a hydraulic and paddiling back into the trough of the wave, somtimes boil line or "chunder pile" the opposite is being surfed in wich you loose control(any you did really have) and you are along for the ride. These can often be retentive hydraulics, if a swimmer finds one they can be held indefinatly depanding on water level or particular hydraulic charteristics.
Drop surfing- instead of paddiling back in as above, you take foward momentum into the hydraulic and instead of "T- ing" up to it you hit the hole with an angle and spin upstream to stay in the hydraulic and start surfing, or begin being surfed. Advaneced Manuever! Always be aware of what is down stream before attempting any surfing intentionally.
Nose dunks – Large self-bailing rafts can enter hydraulics called holes from downstream and submerge their nose, or reverse taco. This can be a safe way to get rafters wet in a hydraulic. (see surfing)
Pirouette – A move executed by either a sweep or draw stroke, sending the raft spinning with the current. Often useful for avoiding obstacles.
Back Pivot - Turning the raft from a ferry angle to a bow-downstream position. Used in tight places to recover from an extreme ferry angle, this maneuver narrows the passing space of the boat and allows it to slide closely past obstructions.


Safety
White water rafting can be a dangerous sport, especially if basic safety precautions are not observed. That said, fatalities are rare in both commercial and private rafting. Meta-analyses have calculated fatalities fell between 0.55 - 0.86% per 100,000 user days. Studies have shown that injury rates in rafting are relatively low, however may be skewed due to a large number of unreported incidents. Typical rafting injuries include trauma from striking an object, traumatic stress from the interaction of the paddler’s positioning and equipment and the force of the water, overuse injuries, and submersion/environmental injuries, non environmental, undisclosed medical conditions (such as heart problems).

Depending on the area, safety regulations covering raft operators may exist in legislation. These range from certification of outfitters, rafts, and raft leaders, to more stringent regulations about equipment and procedures. It is generally advisable to discuss safety measures with a rafting operator before signing on for a trip. The equipment used and the qualifications of the company and raft guides are essential information to be considered.

Like most outdoor sports, rafting in general has become safer over the years. Expertise in the sport has increased, and equipment has become more specialized and improved in quality. As a result, the difficulty rating of most river runs has changed. A classic example would be the Colorado River in the Grand Canyon, which has swallowed whole expeditions in the past, leaving only fragments of boats. In contrast, it is now run safely by commercial outfitters hundreds of times each year with relatively untrained passengers.

Risks in white water rafting stem from both environmental dangers and from improper behavior. Certain features on rivers are inherently unsafe and have remained consistently so despite the passage of time. These would include ‘keeper hydraulics’, ‘strainers’ (e.g. fallen trees), dams (especially low-head dams, which tend to produce river-wide keeper hydraulics), undercut rocks, and of course dangerously high waterfalls. Rafting with experienced guides is the safest way to avoid such features. Even in safe areas, however, moving water can always present risks—such as when a swimmer attempts to stand up on a rocky riverbed in strong current, risking foot entrapment. Irresponsible behavior related to rafting while intoxicated has also contributed to many accidents.

To combat the illusion that rafting is akin to an amusement park ride, and to underscore the personal responsibility each rafter faces on a trip, rafting outfitters generally require customers to sign waiver forms indicating understanding and acceptance of potential serious risks. Rafting trips often begin with safety presentations to educate customers about problems that may arise.

White water rafting is often played for the adrenaline rush and this can become a problem for participants' safety. White water rafting accidents have occurred but are not common.

Due to this the overall risk level on a rafting trip with experienced guides using proper precautions is low. Thousands of people safely enjoy raft trips every year.

Environmental issues

Like all outdoor activities, rafting must balance its use of nature with the conservation of rivers as a natural resource and habitat. Because of these issues, some rivers now have regulations restricting the annual and daily operating times or numbers of rafters.

Conflicts have arisen when rafting operators, often in co-operation with municipalities and tourism associations, alter the riverbed by dredging and/or blasting in order to eliminate safety hazards or create more interesting whitewater features in the river. Environmentalists argue that this may have negative impacts to riparian and aquatic ecosystems, while proponents claim these measures are usually only temporary, since a riverbed is naturally subject to permanent changes during large floods and other events.

Rafting contributes to the economy of many regions which in turn may contribute to the protection of rivers from hydroelectric power generation, diversion for irrigation, and other development. Additionally, white water rafting trips can promote environmentalism. Commercial rafting companies that employ professional raft guides to lead multi-day trips through the National Wild and Scenic Rivers System have the potential to develop the environmental stewardship and general environmental behaviors of visitors. Studies suggest that environmental efficacy increases when there is an increase in the length of the trip, daily immersion, and the amount of resource interpretation by the guide. Educating visitors has the potential to counteract negative affects of that visitation. By experiencing firsthand the beauty of a river, individuals who would otherwise be indifferent to environmental issues may gain a strong desire to protect and preserve that area because of their positive outdoor experience.

Surfing

Surfing is a surface water sport in which the wave rider, referred to as a surfer, rides on the forward or deep face of a moving wave, which is usually carrying the surfer towards the shore. Waves suitable for surfing are primarily found in the ocean, but can also be found in lakes or in rivers in the form of a standing wave or tidal bore. However, surfers can also utilize artificial waves such as those from boat wakes and the waves created in artificial wave pools.


Synchronised surfing, Manly Beach, New South Wales, 1938-46
The term surfing refers to the act of riding a wave, regardless of whether the wave is ridden with a board or without a board, and regardless of the stance used (goofy or regular stance). The native peoples of the Pacific, for instance, surfed waves on alaia, paipo, and other such craft, and did so on their belly and knees. The modern-day definition of surfing, however, most often refers to a surfer riding a wave standing up on a surfboard; this is also referred to as stand-up surfing.

One variety of stand-up surfing is paddle boarding. Another prominent form of surfing is body boarding, when a surfer rides a wave on a bodyboard, either lying on their belly, drop knee, or sometimes even standing up on a body board. Other types of surfing include knee boarding, surf matting (riding inflatable mats), and using foils. Body surfing, where the wave is surfed without a board, using the surfer's own body to catch and ride the wave, is very common and is considered by some to be the purest form of surfing.

Three major subdivisions within standing-up surfing are long boarding, short boarding, and stand up paddle surfing (SUP), and these three have several major differences, including the board design and length, the riding style, and the kind of wave that is ridden.

In tow-in surfing (most often, but not exclusively, associated with big wave surfing), a motorized water vehicle, such as a personal watercraft, tows the surfer into the wave front, helping the surfer match a large wave's speed, which is generally a higher speed than a self-propelled surfer can produce. Surfing-related sports such as paddle boarding and sea kayaking do not require waves, and other derivative sports such as kite surfing and windsurfing rely primarily on wind for power, yet all of these platforms may also be used to ride waves. Recently with the use of V-drive boats, Wakesurfing, in which one surfs on the wake of a boat, has emerged. The Guinness Book of World Records recognized a 78 feet (23.8 m) wave ride by Garrett McNamara at Nazaré, Portugal as the largest wave ever surfed, although this remains an issue of much contention amongst many surfers, given the difficulty of measuring a constantly changing mound of water

Origins and history
For centuries, surfing was a central part of ancient Polynesian culture. Surfing may have first been observed by Europeans at Tahiti in 1767 by Samuel Wallis and the crew members of the Dolphin who were the first Europeans to visit the island in June of that year. Another candidate is the botanist Joseph Banks being part of the first voyage of James Cook on the HMS Endeavour, who arrived on Tahiti on 10 April 1769. Lieutenant James King was the first person to write about the art of surfing on Hawaii when he was completing the journals of Captain James Cook upon Cook's death in 1779.

When Mark Twain visited Hawaii in 1866 he wrote,

In one place we came upon a large company of naked natives, of both sexes and all ages, amusing themselves with the national pastime of surf-bathing.

References to surf riding on planks and single canoe hulls are also verified for pre-contact Samoa, where surfing was called fa'ase'e or se'egalu (see Augustin Krämer, The Samoa Islands), and Tonga, far pre-dating the practice of surfing by Hawaiians and eastern Polynesians by over a thousand years.

In July 1885, three teenage Hawaiian princes took a break from their boarding school, St. Mathew’s Hall in San Mateo, and came to cool off in Santa Cruz, California. There, David Kawananakoa, Edward Keliiahonui and Jonah Kuhio Kalaniana'ole surfed the mouth of the San Lorenzo River on custom-shaped redwood boards, according to surf historians Kim Stoner and Geoff Dunn.

George Freeth (8 November 1883 – 7 April 1919) is often credited as being the "Father of Modern Surfing". He is thought to have been the first modern surfer.

In 1907, the eclectic interests of the land baron Henry Huntington brought the ancient art of surfing to the California coast. While on vacation, Huntington had seen Hawaiian boys surfing the island waves. Looking for a way to entice visitors to the area of Redondo Beach, where he had heavily invested in real estate, he hired a young Hawaiian to ride surfboards. George Freeth decided to revive the art of surfing, but had little success with the huge 16-foot hardwood boards that were popular at that time. When he cut them in half to make them more manageable, he created the original "Long board", which made him the talk of the islands. To the delight of visitors, Freeth exhibited his surfing skills twice a day in front of the Hotel Redondo.

In 1975, professional contests started. That year Margo Oberg became the first female professional surfer.

Surf waves
Swell is generated when wind blows consistently over a large area of open water, called the wind's fetch. The size of a swell is determined by the strength of the wind and the length of its fetch and duration. Because of this, surf tends to be larger and more prevalent on coastlines exposed to large expanses of ocean traversed by intense low pressure systems.

Local wind conditions affect wave quality, since the surface of a wave can become choppy in blustery conditions. Ideal conditions include a light to moderate "offshore" wind, because it blows into the front of the wave, making it a "barrel" or "tube" wave. Waves are Left handed and Right Handed depending upon the breaking formation of the wave.

Waves are generally recognized by the surfaces over which they break. For example, there are Beach breaks, Reef breaks and Point breaks.

The most important influence on wave shape is the topography of the seabed directly behind and immediately beneath the breaking wave. The contours of the reef or bar front becomes stretched by diffraction. Each break is different, since each location's underwater topography is unique. At beach breaks, sandbanks change shape from week to week. Surf forecasting is aided by advances in information technology. Mathematical modeling graphically depicts the size and direction of swells around the globe.

Swell regularity varies across the globe and throughout the year. During winter, heavy swells are generated in the mid-latitudes, when the North and South polar fronts shift toward the Equator. The predominantly Westerly winds generate swells that advance Eastward, so waves tend to be largest on West coasts during winter months. However, an endless train of mid-latitude cyclones cause the isobars to become undulated, redirecting swells at regular intervals toward the tropics.

East coasts also receive heavy winter swells when low-pressure cells form in the sub-tropics, where slow moving highs inhibit their movement. These lows produce a shorter fetch than polar fronts, however they can still generate heavy swells, since their slower movement increases the duration of a particular wind direction. The variables of fetch and duration both influence how long wind acts over a wave as it travels, since a wave reaching the end of a fetch behaves as if the wind died.

During summer, heavy swells are generated when cyclones form in the tropics. Tropical cyclones form over warm seas, so their occurrence is influenced by El Niño & La Niña cycles. Their movements are unpredictable.


Surf travel and some surf camps offer surfers access to remote, tropical locations, where tradewinds ensure offshore conditions. Since winter swells are generated by mid-latitude cyclones, their regularity coincides with the passage of these lows. Swells arrive in pulses, each lasting for a couple of days, with a few days between each swell.

Artificial reefs
The value of good surf in attracting surf tourism has prompted the construction of artificial reefs and sand bars. Artificial surfing reefs can be built with durable sandbags or concrete, and resemble a submerged breakwater. These artificial reefs not only provide a surfing location, but also dissipate wave energy and shelter the coastline from erosion. Ships such as Seli 1 that have accidentally stranded on sandy bottoms, can create sandbanks that give rise to good waves.

An artificial reef known as Chevron Reef was constructed in El Segundo, California in hopes of creating a new surfing area. However, the reef failed to produce any quality waves and was removed in 2008. In Kovalam, South West India, an artificial reef has, however, successfully provided the local community with a quality lefthander, stabilized coastal soil erosion, and provided good habitat for marine life. ASR Ltd., a New Zealand-based company, constructed the Kovalam reef and is working on another reef in Boscombe, England.

Even with artificial reefs in place, a tourist's vacation time may coincide with a "flat spell", when no waves are available. Completely artificial Wave pools aim to solve that problem by controlling all the elements that go into creating perfect surf, however there are only a handful of wave pools that can simulate good surfing waves, owing primarily to construction and operation costs and potential liability. Most wave pools generate waves that are too small and lack the power necessary to surf. The Seagaia Ocean Dome, located in Miyazaki, Japan, was an example of a surfable wave pool. Able to generate waves with up to 10-foot faces, the specialized pump held water in 20 vertical tanks positioned along the back edge of the pool. This allowed the waves to be directed as they approach the artificial sea floor. Lefts, Rights, and A-frames could be directed from this pump design providing for rippable surf and barrel rides. The Ocean Dome cost about $2 billion to build and was expensive to maintain. The Ocean Dome was closed in 2007. In England, construction is nearing completion on the The Wave, situated near Bristol, which will enable people unable to get to the coast to enjoy the waves in a controlled environment, set in the heart of nature.

Surfers and surf culture
Surfers represent a diverse culture based on riding the waves. Some people practice surfing as a recreational activity while others make it the central focus of their lives. Within the United States, surfing culture is most dominant in Hawaii and California because these two states offer the best surfing conditions. However, waves can be found wherever there is coastline, and a tight-knit yet far-reaching subculture of surfers has emerged throughout America. Some historical markers of the culture included the woodie, the station wagon used to carry surfers' boards, as well as boardshorts, the long swim shorts typically worn while surfing. Surfers also wear wetsuits in colder regions.

The sport of surfing now represents a multi-billion dollar industry especially in clothing and fashion markets. The World Surf League (WSL) runs the championship tour, hosting top competitors in some of the best surf spots around the globe. A small number of people make a career out of surfing by receiving corporate sponsorships and performing for photographers and videographers in far-flung destinations; they are typically referred to as freesurfers.

When the waves were flat, surfers persevered with sidewalk surfing, which is now called skateboarding. Sidewalk surfing has a similar feel to surfing and requires only a paved road or sidewalk. To create the feel of the wave, surfers even sneak into empty backyard swimming pools to ride in, known as pool skating. Eventually, surfing made its way to the slopes with the invention of the Snurfer, later credited as the first snowboard. Many other board sports have been invented over the years, but all can trace their heritage back to surfing.

Many surfers claim to have a spiritual connection with the ocean, describing surfing, the surfing experience, both in and out of the water, as a type of spiritual experience or a religion.


Maneuvers
Standup surfing begins when the surfer paddles toward shore in an attempt to match the speed of the wave (The same applies whether the surfer is standup paddling, bodysurfing, boogie-boarding or using some other type of watercraft, such as a waveski or kayak.). Once the wave begins to carry the surfer forward, the surfer stands up and proceeds to ride the wave. The basic idea is to position the surfboard so it is just ahead of the breaking part (whitewash) of the wave. A common problem for beginners is being able to catch the wave at all.


Surfers' skills are tested by their ability to control their board in difficult conditions, riding challenging waves, and executing maneuvers such as strong turns and cutbacks (turning board back to the breaking wave) and carving (a series of strong back-to-back maneuvers). More advanced skills include the floater (riding on top of the breaking curl of the wave), and off the lip (banking off the breaking wave). A newer addition to surfing is the progression of the air whereby a surfer propels off the wave entirely up into the air, and then successfully lands the board back on the wave.
The tube ride is considered to be the ultimate maneuver in surfing. As a wave breaks, if the conditions are ideal, the wave will break in an orderly line from the middle to the shoulder, enabling the experienced surfer to position themselves inside the wave as it is breaking. This is known as a tube ride. Viewed from the shore, the tube rider may disappear from view as the wave breaks over the rider's head. The longer the surfer remains in the tube, the more successful the ride. This is referred to as getting tubed, barreled, shacked or pitted. Some of the world's best known waves for tube riding include Pipeline on the North shore of Oahu, Teahupoo in Tahiti and G-Land in Java. Other names for the tube include "the barrel", and "the pit".

Hanging ten and hanging five are moves usually specific to long boarding. Hanging Ten refers to having both feet on the front end of the board with all of the surfer's toes off the edge, also known as nose-riding. Hanging Five is having just one foot near the front, with five toes off the edge.

Cutback: Generating speed down the line and then turning back to reverse direction.

Floater: Suspending the board atop the wave. Very popular on small waves.

Top-Turn: Turn off the top of the wave. Sometimes used to generate speed and sometimes to shoot spray.

Air / Aerial: Launching the board off the wave entirely, then re-entering the wave. Various airs include ollies, lien airs, method airs, and other skateboard-like maneuvers.

Terms
The Glossary of surfing includes some of the extensive vocabulary used to describe various aspects of the sport of surfing as described in literature on the subject. In some cases terms have spread to a wider cultural use. These terms were originally coined by people who were directly involved in the sport of surfing.

Learning
Many popular surfing destinations have surf schools and surf camps that offer lessons. Surf camps for beginners and intermediates are multi-day lessons that focus on surfing fundamentals. They are designed to take new surfers and help them become proficient riders. All-inclusive surf camps offer overnight accommodations, meals, lessons and surfboards. Most surf lessons begin with instruction and a safety briefing on land, followed by instructors helping students into waves on longboards or "softboards". The softboard is considered the ideal surfboard for learning, due to the fact it is safer, and has more paddling speed and stability than shorter boards. Funboards are also a popular shape for beginners as they combine the volume and stability of the longboard with the manageable size of a smaller surfboard. New and inexperienced surfers typically learn to catch waves on softboards around the 7–8 foot funboard size. Due to the softness of the surfboard the chance of getting injured is substantially minimized. Costco's alaia design Wavestorm surfboard is a cheap and cost efficient option; unlike many surfboards, this one comes with rubber fins, stock leash, pre-installed traction.

Typical surfing instruction is best performed one-on-one, but can also be done in a group setting. The most popular surf locations offer perfect surfing conditions for beginners, as well as challenging breaks for advanced students. The ideal conditions for learning would be small waves that crumble and break softly, as opposed to the steep, fast-peeling waves desired by more experienced surfers. When available, a sandy seabed is generally safer.

Surfing can be broken into several skills: Paddling strength, Positioning to catch the wave, timing, and balance. Paddling out requires strength, but also the mastery of techniques to break through oncoming waves (duck diving, eskimo roll). Take-off positioning requires experience at predicting the wave set and where they will break. The surfer must pop up quickly as soon as the wave starts pushing the board forward. Preferred positioning on the wave is determined by experience at reading wave features including where the wave is breaking. Balance plays a crucial role in standing on a surfboard. Thus, balance training exercises are a good preparation. Practicing with a Balance board or swing boarding helps novices master the art.


Equipment
Surfing can be done on various equipment, including surfboards, longboards, Stand Up Paddle boards (SUP's), bodyboards, wave skis, skimboards, kneeboards, surf mats and macca's trays. Surfboards were originally made of solid wood and were large and heavy (often up to 12 ft or 3.7 m long and 150 lb or 68 kg). Lighter balsa wood surfboards (first made in the late 1940s and early 1950s) were a significant improvement, not only in portability, but also in increasing maneuverability.

Most modern surfboards are made of fiberglass foam (PU), with one or more wooden strips or "stringers", fiberglass cloth, and polyester resin (PE). An emerging board material is epoxy resin and Expanded Polystyrene foam (EPS) which is stronger and lighter than traditional PU/PE construction. Even newer designs incorporate materials such as carbon fiber and variable-flex composites in conjunction with fiberglass and epoxy or polyester resins. Since epoxy/EPS surfboards are generally lighter, they will float better than a traditional PU/PE board of similar size, shape and thickness. This makes them easier to paddle and faster in the water. However, a common complaint of EPS boards is that they do not provide as much feedback as a traditional PU/PE board. For this reason, many advanced surfers prefer that their surfboards be made from traditional materials.

Other equipment includes a leash (to stop the board from drifting away after a wipeout, and to prevent it from hitting other surfers), surf wax, traction pads (to keep a surfer's feet from slipping off the deck of the board), and fins (also known as skegs) which can either be permanently attached (glassed-on) or interchangeable. Sportswear designed or particularly suitable for surfing may be sold as boardwear (the term is also used in snowboarding). In warmer climates, swimsuits, surf trunks or boardshorts are worn, and occasionally rash guards; in cold water surfers can opt to wear wetsuits, boots, hoods, and gloves to protect them against lower water temperatures. A newer introduction is a rash vest with a thin layer of titanium to provide maximum warmth without compromising mobility. In recent years, there have been advancements in technology that have allowed surfers to pursue even bigger waves with added elements of safety. Big wave surfers are now experimenting with inflatable vests or colored dye packs to help decrease their odds of drowning.

There are many different surfboard sizes, shapes, and designs in use today. Modern longboards, generally 9 to 10 feet (2.7 to 3.0 m) in length, are reminiscent of the earliest surfboards, but now benefit from modern innovations in surfboard shaping and fin design. Competitive longboard surfers need to be competent at traditional walking manoeuvres, as well as the short-radius turns normally associated with shortboard surfing. The modern shortboard began life in the late 1960s and has evolved into today's common thruster style, defined by its three fins, usually around 6 to 7 feet (1.8 to 2.1 m) in length. The thruster was invented by Australian shaper Simon Anderson.

Midsize boards, often called funboards, provide more maneuverability than a longboard, with more flotation than a shortboard. While many surfers find that funboards live up to their name, providing the best of both surfing modes, others are critical.

"It is the happy medium of mediocrity," writes Steven Kotler. "Funboard riders either have nothing left to prove or lack the skills to prove anything."
There are also various niche styles, such as the Egg, a longboard-style short board targeted for people who want to ride a shortboard but need more paddle power. The Fish, a board which is typically shorter, flatter, and wider than a normal shortboard, often with a split tail (known as a swallow tail). The Fish often has two or four fins and is specifically designed for surfing smaller waves. For big waves there is the Gun, a long, thick board with a pointed nose and tail (known as a pin tail) specifically designed for big waves.

The physics of surfing
The physics of surfing involves the physical oceanographic properties of wave creation in the surf zone, the characteristics of the surfboard, and the surfer's interaction with the water and the board.

Wave formation
Ocean waves are defined as a collection of dislocated water parcels that undergo a cycle of being forced passed their normal position and being restored back to their normal position. Wind caused ripples and eddies form waves that gradually gain speed and distance (fetch). Waves increase in energy and speed, and then become longer and stronger. The fully developed sea has the strongest wave action that experiences storms lasting 10-hours and creates 15 meter wave heights in the open ocean.

The waves created in the open ocean are classified as deep-water waves. Deep-water waves have no bottom interaction and the orbits of these water molecules are circular; their wavelength is short relative to water depth and the velocity decays before the reaching the bottom of the water basin. Deep waves have depths greater than ½ their wavelengths. Wind forces waves to break in the deep sea.

Deep-water waves travel to shore and become shallow water waves. Shallow water waves have depths less than ½ of their wavelength. Shallow wave's wavelengths are long relative to water depth and have elliptical orbitals. The wave velocity effects the entire water basin. The water interacts with the bottom as it approaches shore and has a drag interaction. The drag interaction pulls on the bottom of the wave, causes refraction, increases the height, decreases the celerity (or the speed of the wave form), and the top (crest) falls over. This phenomenon happens because the velocity of the top of the wave is greater than the velocity of the bottom of the wave.

The surf zone is place of convergence of multiple waves types creating complex wave patterns. A wave suitable for surfing results from maximum speeds of 5 meters per second. This speed is relative because local onshore winds can cause waves to break. In the surf zone, shallow water waves are carried by global winds to the beach and interact with local winds to make surfing waves.

Different onshore and off shore wind patterns in the surf zone create =different types of waves. Onshore winds cause random wave breaking patterns and are more suitable for experienced surfers. Light offshore winds create smoother waves, while strong direct offshore winds cause plunging or large barrel waves. Barrel waves are large because the water depth is small when the wave breaks. Thus, the breaker intensity (or force) increases, and the wave speed and height increase. Off shore winds produce non-surfable conditions by flattening a weak swell. Weak swell is made from surface gravity forces and has long wavelengths.

Wave conditions for surfing
Surfing waves can be analyzed using the following parameters: breaking wave height, wave peel angle (α), wave breaking intensity, and wave section length. The breaking wave height has two measurements, the relative heights estimated by surfers and the exact measurements done by physical oceanographers. Measurements done by surfers were 1.36 to 2.58 times higher than the measurements done by scientists. The scientifically concluded wave heights that are physically possible to surf are 1 to 20 meters.

The wave peel angle is one of the main constituents of a potential surfing wave. Wave peel angle measures the distance between the peel-line and the line tangent to the breaking crest line. This angle controls the speed of the wave crest. The speed of the wave is an addition of the propagation velocity vector (Vw) and peel velocity vector (Vp), which results in the overall velocity of the wave (Vs).


Wave breaking intensity measures the force of the wave as it breaks, spills, or plunges (a plunging wave is termed by surfers as a “barrel wave”). Wave section length is the distance between two breaking crests in a wave set. Wave section length can be hard to measure because local winds, non-linear wave interactions, island sheltering, and swell interactions can cause multifarious wave configurations in the surf zone.

Slacklining

Slacklining refers to use of webbing tensioned between two anchor points to balance and walk. Slacklining resembles slack rope walking and tightrope walking as the line is held under tension. Slacklines differ from tightwires and tightropes in that they are tensioned to create a dynamic line with stretch and bounce like a long and narrow trampoline. Tension can be adjusted to suit the user, and different webbing can be used for a variety of tricks. The line itself is flat. Slacklining is popular due to its simplicity and versatility. It can be used in various environments

Slackline Setup
Setup
Slacklines can be set up in two principal ways: in two sections of webbing with a tensioner or with three sections of webbing and a tensioner.

Two-Section Setup
The two-section setup consists of: a long (30–100-foot, 9–30-metre) piece of two-or-one-inch (5.1 or 2.5 cm) webbing with a loop sewn on one end, allowing it to cinch tightly around a tree. The second section is typically much shorter (10 ft, 3 m) and has a similar sewn loop on one end, allowing it to cinch around a tree while the other end of this shorter piece of webbing is sewn to a ratchet. The ratchet allows these two sections of webbing to be connected and tensioned to the user's specifications.

Three-Section Setup
The three-section setup consists of: a long section of webbing (30–100 ft, 9–30 m) strung tightly and connected to the two shorter sections (8–12 ft, 2.5–3.5 m) that are called "tree slings" and are used as anchors on either end. The most difficult and widely discussed element of a slackline setup is the tensioning system. Common setups include simple friction methods, using wraps of webbing between two carabiners, a ratchet, a comealong, a carabiner pulley system, a roped pulley system, or a commercial slackline kit.

Tree anchors
The most common anchors for slacklines are trees. Trees greater than 12 inches (30 cm) in diameter are considered ideal in most cases. There are several very effective methods of tree protection that function on two principles: eliminating abrasion, and redistributing the load over a wider area. One of the most effective means of tree protection is a wrap of vertical blocks (1 in × 1 in (2.5 cm × 2.5 cm) cut into 6 in (15 cm) pieces) strung together by drilling a small-diameter hole through the center and running cord through them. Blocks are spaced evenly to prevent the anchor slings from contacting and abrading the outer bark, and the length of the blocks distributes the load vertically as opposed to horizontally, compressing a continuous line around the trunk. The addition of a carpet square between the block wrap and the outer bark is considered ideal among the founding community of slackliners. Many other ways to protect the tree are commonly used, such as towels, mats, cardboard, carpet and purpose-made tree protectors.

Using carpet squares or cardboard even, by themselves, addresses only abrasion, leaving the load concentrated on a small area of the tree. These methods are adequate for occasional use, but with the high tension of longlines, one who slacklines regularly should take every precaution to protect the life of the tree.

Variations

A special characteristic of slacklining is the ease with which the dynamics of the practice can be altered. Using narrow (5⁄8 inch, 1.6 cm) webbing will result in a stretchier slackline. This allows for more sway in the line and can make a short line feel substantially longer. Wider webbing (2 inches, 5 cm) is much more rigid, often creating a bouncier slackline optimal for aerial tricks. The tension of the line will also increase or decrease the sway of the line. Weight due to the different methods of tensioning will also vary the performance of a slackline. A comealong and a ratchet will both add enough weight to allow the feedback from quick movements on shorter slacklines to be felt.

Styles of slacklining
Urbanlining
Urbanlining or urban slacklining combines all the different styles of slacklining. It is practiced in urban areas, for example in city parks and on the streets. Most urban slackliners prefer wide 2-inch (5 cm) lines for tricklining on the streets, but some may use narrow (5⁄8 or 1 inch, 1.6 or 2.5 cm) lines for longline purposes or for waterlining. Also see the other sections of slackline styles below.


First category is called timelining, which means a person is trying to be on slackline for as long as possible without falling down — one hour, two hours etc. This takes tremendous concentration and focus of will, and is a great endurance training for postural muscles.

Second is streetlining which is combining street workout power moves with slackline dynamic shaky bouncy feeling. Main focus are static handstands, super splits — hands and feet together, planche, front lever, back lever, one arm handstand and other interesting extreme moves that are evolving in street workout culture.

Tricklining
Tricklining has become the most common form of slacklining due to the easy setup of 2-inch (5 cm) slackline kits. Tricklining is often done low to the ground but can be done on highlines as well. A great number of tricks can be done on the line, and because the sport is fairly new, there is plenty of room for new tricks. Some of the basic tricks done today are walking, walking backwards, turns, drop knee, running and jumping onto the slackline to start walking, and bounce walking. Some intermediate tricks include: Buddha sit, sitting down, lying down, cross-legged knee drop, surfing forward, surfing sideways, and jump turns, or "180s." Some of the advanced tricks are: jumps, tree plants, jumping from line-to-line, 360s, butt bounces, and chest bounces. With advancements in webbing technology the limits for what can be done on a slackline are being pushed constantly. It is not uncommon to see expert slackliners incorporating flips and twists into slackline trick combos.

Waterlining
Waterlining is slacklining over water. This is an ideal way to learn new tricks, or to just have more fun. Common places to set up waterlines are over pools, lakes, rivers, creeks, between pier or railroad track pillars, and boat docks. The slackline can be set up high over the surface of the water, close to the surface or even underneath the surface. It is important, however, that the water be deep enough, free from obstacles, and that the area should not be traveled by boats.

Highlining
Man highlining at Taft Point in Yosemite National Park with El Capitan in the background.
Highlining is slacklining at elevation above the ground or water. Many slackliners consider highlining to be the pinnacle of the sport. Highlines are commonly set up in locations that have been used or are still used for Tyrolean traverse. When rigging highlines, experienced slackers take measures to ensure that solid, redundant and equalized anchors are used to secure the line into position. Modern highline rigging typically entails a mainline of webbing, backup webbing, and either climbing rope or amsteel rope for redundancy. However, many highlines are rigged with a mainline and backup only, especially if the highline is low tension (less than 900 lbf (410 kgf; 4,000 N)), or rigged with high quality webbing like Type 18 or MKII Spider Silk. It is also common to pad all areas of the rigging which might come in contact with abrasive surfaces. To ensure safety, most highliners wear a climbing harness or swami belt with a leash attached to the slackline itself. Leash-less, or "free-solo" slacklining – a term borrowed from rockclimbing – is not unheard of, however, with proponents such as Dean Potter and Andy Lewis.

Tunelining
Tunelining is slacklining while playing a musical instrument.

Slackline Yoga
Another form of slacklining is Slackline Yoga, also referred to as YogaSlacking or Slackasana. Slackline Yoga takes traditional yoga poses and moves them to the slackline. It has been described as "distilling the art of yogic concentration." To balance on a 1-inch (2.5 cm) piece of webbing lightly tensioned between two trees is not easy, and doing yoga poses on it is even more challenging. The practice has many layers, simultaneously developing focus, dynamic balance, power, breath, core integration, flexibility, and confidence. Utilizing standing postures, sitting postures, arm balances, kneeling postures, inversions and unique vinyasa, a skilled slackline yogi is able to create a flowing yoga practice without ever falling from the line.

Split on a slackline
In 2005, Sam Salwei and Jason Magness began demonstrating yoga poses on a slackline at the Yoga Journal conference in Estes Park, later forming YogaSlackers. Since then, the members of team YogaSlackers have collectively taught over 5000 people to successfully embrace this form of asana. They have developed a special slackline and simple tensioning system, allowing for practitioners to learn safely and experience the benefit of a wide range of dynamic energies while on the line.

Another group of "slackline yogis" are the Rocky Mountain Slackline Crew out of Fort Collins, CO. The company has been involved with local and state wide yoga studios incorporating slackline into their class curriculum. They have created a series of postures, maneuvers, and breath rhythm to bring the riders a challenging and rewarding experience.

Slackline Yoga has been reported in The Wall Street Journal, Yoga Journal and Climbing Magazine.

Freestyle slacklining
Freestyle slacklining (a.k.a. “rodeo slacklining") is the art and practice of cultivating balance on a piece of rope or webbing draped slack between two anchor points, typically about 15 to 30 feet (4.6 to 9.1 m) apart and 2 to 3 feet (60 to 90 cm) off the ground in the center. This type of very "slack" slackline provides a wide array of opportunities for both swinging and static maneuvers. A freestyle slackline has no tension in it, while both traditional slacklines and tightropes are tensioned. This slackness in the rope or webbing allows it to swing at large amplitudes and adds a different dynamic. This form of slacklining first came into popularity in 1999, through a group of students from Colby College, in Waterville ME. It was first written about on a website called the "Vultures Peak Center for Freestyle and Rodeo Slackline Research" in 2004. The article "Old Revolution — New Recognition - 3-10-04" describes these early developments in detail.

Windlining
Windlining is a practice of slacklining performed in very windy conditions. Depending on the intensity of the wind, it can be difficult to remain on the line without being blown off. The sensation one experiences is like flying as the slacker must angle his body and arms in an aerodynamic manner to maintain balance.

History
While rope walking has been around in one manner or another for thousands of years, the origins of modern day slacklining is generally attributed to a young rock climber named Adam Grosowsky from Southern Illinois in 1976. A then sixteen-year-old Adam, the son of the head of SIUs Design Department, became obsessed with a photo he found in the university library with the following understated caption: Circus Performers c1890 which depicted a wire bolted low on a wall on one end and the other terminating in a wristloop held by a performer doing a one-hand handstand on the top of a flagpole with his body canted far to the opposite side counterbalancing the weight of the wire. In the middle of that wire was another performer in a handstand. Adam successfully harassed the small band of local climbers into almost believing they could reproduce this feat. They all set about learning to walk on climbing ropes, webbing, chains and low / high wires, but only Adam managed to carry through with achieving some elements of that historic circus feat, most notably being able to maintain an indefinite handstand on 1-inch (2.5 cm) webbing and even getting it rocking side-to-side while in the handstand. Adam carried those bad habits to Olympia, Washington's The Evergreen State College in 1979. where he met fellow climbers Jeff Ellington and Brooke Sandahl. Adam set up his permanent heavy highwire in the woods on campus while the trio continued to perfect walking, handstands, and jump mounts on webbing. Their handstand work focused on 1-inch (2.5 cm) flat climbing webbing and they also employed the dynamics and flexibility of the nylon webbing to develop all manner of other tricks, including a three-club passing (juggling) routine between two slackliners balanced simultaneously on the same line. Red Square, Evergreen's central campus plaza, was a convenient between-class practice area where they often drew crowds of spectators. Grosowsky, along with Ellington were fascinated with wirewalking history and circus culture from the start, and in 1981 performed leashless on a 30-foot (9 m) highline strung 25 feet (8 m) over a concrete floor as part of a project to recreate a traditional one-ring circus in The Evergreen State College's main performance auditorium. During this period Grosowsky, who is now a regionally well-known Northwest artist, devoted much of his lithographic art to themes involving wirewalking and circus culture. The sport blossomed within the West Coast rock climbing community, and then branched out elsewhere all over the world.

Highlining history
Highlining was inspired by a number of “high wire” artists who walked steel cable up high in unique places. From 1907-1948, Mr. Ivy Baldwind of Eldorado Springs, Colorado crossed Eldorado Canyon on a high wire numerous times. His final crossing was documented on his 82nd birthday. On August 7, 1974 Philippe Petit set-up and crossed a high wire between the Twin Towers of the World Trade Center in New York. In the summer of 1983, Adam Grosowsky and Jeff Ellington set up a 55-foot (17 m) high wire at Yosemite's Lost Arrow Spire that was nearly 2,890 feet (880 m) high. However, neither of them were able to completely cross this line due to inadequate guying. In the autumn of 1983, inspired by Jeff and Adam's efforts, a 20-year-old Scott Balcom and 17-year-old Chris Carpenter successfully completed what is believed to be the first documented high walk on nylon webbing, instead of using cable, giving birth to what slackliners now call highlining. This first highline, referred to as The Arches, was a span about 30 feet (9 m) long and about 120 feet (35 m) above ground in Pasadena, California under the 134 Freeway bridge, between two arches that spanned the trickling Arroyo Seco below. The next summer (1984), Scott Balcom set up a highline on Yosemite’s Lost Arrow Spire with the help of Darrin Carter and Chris Carpenter. Scott’s attempt, however, was unsuccessful (neither Darrin nor Chris made an attempt). On July 13, 1985, Scott Balcom returned and successfully crossed the now-famous Lost Arrow Spire highline. In June 1990, Chris Carpenter purposefully "surfed" a highline spanning the gap of Horsetooth Rock in Fort Collins, Colorado. In 1993, Darrin Carter became the second person to successfully cross the Lost Arrow Spire highline. In 1995, Darrin Carter performed unprotected crossings of the Lost Arrow Spire in Yosemite and The Fins, in Tucson, AZ on Mt. Lemmon highway. On July 16, 2007, Libby Sauter became the first woman to successfully cross the Lost Arrow Spire, with Jenna McLennan walking it shortly after. In 2008, Dean Potter became the first person to BASE jump from a highline at Hell Roaring Canyon in Utah. On September 10, 2011, Chris Rigby and Balance Community: Slackline Outfitters owner Jerry Miszewski established the Balance Community Highline Festival in Garden Valley, California. There has been a highline fest each month since; nine highlines are set up, ranging 35 to 400 feet (10 to 120 m) long for highliners from across the U.S. to come train on.

Competitive sport history
Since 2010 the World Slackline Federation has tried to establish tricklining as a competitive sport. Jumps and other tricks are judged according to five criteria: Difficulty, technique, diversity, amplitude (of jumps) and performance. Competitions are held on several levels.

Tricklining history
Andy Lewis is known for having the longest history in competitive slacklining. He is considered to be the father of modern day tricklining and has been the Overall World Champion of Competitive Tricklining since 2008. To date, he holds more prestigious international competition titles than anyone. In 2012, he performed a series of tricks during Madonna's Super Bowl XLVI Halftime Show, to a worldwide audience of 114 million people

Longest highline
The longest highline, with a length of 375 metres (1,230 ft), was walked in Yangshuo (PRC) on November 19, 2014 by Alexander Schulz

The longest highline walked by a woman, with a length of 120 metres (390 ft) was set in Vercors (France) on august, 2015 by Laetitia Gonnon.

Longest free solo highline
The longest free solo highline was walked in Squamish, BC on August 2, 2015 by Spencer Seabrooke. At a length of 64 metres (210 ft), 'The Itus' was walked 1 way leashless by Spencer Seabrooke.

The longest free solo highline by a female is held by Faith Dickey, who walked a 28 meter long highline in Ostrov, Czech Republic in August, 2012. The line was 25 meters high.

Highest slackline
The highest slackline on record was walked by Christian Schou on August 3, 2006 at Kjerag in Rogaland, Norway. The slackline was 1,000 metres (3,281 ft) high. The project was repeated by Aleksander Mork in September 2007.

The current record for walking the highest urban highline is held by professional slackliner Reinhard Kleindl, of Austria, who walked a high wire at a height of 607 feet (185 m) on May 25, 2013 in front of the Messeturm Fair Tower in Frankfurt, Germany. "Reinhard Kleindl, 32, used only his arms to balance as he walked twice along a 98-foot-long (30 m) polyester rope anchored to the two wings of Frankfurt's U-shaped skyscraper Tower 185 above hundreds of cheering supporters."

Longest slackline
The longest slackline, with a length of 610 metres (2,000 ft), was walked on May 09, 2015 by Alexander Schulz in Mongolia.

In June 2010 Stefan Junghannß and Damian Jörren walked a 306.8-metre (1,007 ft) slackline

The longest slackline walked by a woman, a length of 230 metres (750 ft) was set September 2014 in Lausanne (CH) by Laetitia Gonnon.