Antiquity

The Tomb of the Diver, dating to 470 BCE, contains a single enigmatic fresco clearly depicting a young man diving into a curling and waving stream of water.

Plunging

Plunging, the first competitive diving sport

Although diving has been a popular pastime across the world since ancient times, the first modern diving competitions were held in England in the 1880s. The exact origins of the sport are unclear, though it likely derives from the act of diving at the start of swimming races.^[2][3] The 1904 book Swimming by Ralph Thomas notes English reports of plunging records dating back to at least 1865.^[4] The 1877 edition to British Rural Sports by John Henry Walsh makes note of a "Mr. Young" plunging 56 feet (17 m) in 1870, and also states that 25 years prior, a swimmer named Drake could cover 53 feet (16 m).^[5]

The English Amateur Swimming Association (at the time called the Swimming Association of Great Britain) first started a "plunging championship" in 1883.^[6][7] The Plunging Championship was discontinued in 1937.

Fancy diving

A man dives into the Great South Bay of Long Island.

Diving into a body of water had also been a method used by gymnasts in Germany and Sweden since the early 19th century. The soft landing allowed for more elaborate gymnastic feats in midair as the jump could be made from a greater height. This tradition evolved into 'fancy diving', while diving as a preliminary to swimming became known as 'Plain diving'.

In England, the practice of high diving – diving from a great height – gained popularity; the first diving stages were erected at the Highgate Ponds at a height of 15 feet (4.6 m) in 1893 and the first world championship event, the National Graceful Diving Competition, was held there by the Royal Life Saving Society in 1895. The event consisted of standing and running dives from either 15 or 30 feet (4.6 or 9.1 m).

It was at this event that the Swedish tradition of fancy diving was introduced to the sport by the athletes Otto Hagborg and C F Mauritzi. They demonstrated their acrobatic techniques from the 10 m diving board at Highgate Pond and stimulated the establishment of the Amateur Diving Association in 1901, the first organization devoted to diving in the world (later amalgamated with the Amateur Swimming Association). Fancy diving was formally introduced into the championship in 1903.^[8][9]

Olympic era

Swedish high diver Arvid Spångberg at the 1908 Olympic Games from the fourth Olympiad

Plain diving was first introduced into the Olympics at the 1904 event.^[10] The 1908 Olympics in London added 'fancy diving' and introduced elastic boards rather than fixed platforms. Women were first allowed to participate in the diving events for the 1912 Olympics in Stockholm.^[8]

In the 1928 Olympics, 'plain' and 'fancy' diving were amalgamated into one event – 'Highboard Diving'. The diving event was first held indoors in the Empire Pool for the 1934 British Empire Games and 1948 Summer Olympics in London.

Synchronized diving

A man and a woman perform synchronized diving in Brazil, 2014.

Synchronized diving was adopted as an Olympic sport in 2000. Two divers form a team and perform dives simultaneously. The dives are identical. It used to be possible to dive opposites, also known as a pinwheel, but this is no longer part of competitive synchronized diving. For example, one diver would perform a forward dive and the other an inward dive in the same position, or one would do a reverse and the other a back movement. In these events, the diving would be judged both on the quality of execution and the synchronicity – in timing of take-off and entry, height and forward travel.

Scoring the dive

There are rules governing the scoring of a dive. Usually a score considers three elements of the dive: the approach, the flight, and the entry. The primary factors affecting the scoring are:

• if a hand-stand is required, the length of time and quality of the hold
• the height of the diver at the apex of the dive, with extra height resulting in a higher score
• the distance of the diver from the diving apparatus throughout the dive (a diver must not be dangerously close, should not be too far away, but should ideally be within 2 feet (0.61 m) of the platform)
• the properly defined body position of the diver according to the dive being performed, including pointed toes and feet touching at all times
• the proper amounts of rotation and revolution upon completion of the dive and entry into the water
• angle of entry – a diver should enter the water straight, without any angle.
• amount of splash – many judges award divers for the amount of splash created by the diver on entry, with less splash resulting in a higher score.

Each dive is assigned a degree of difficulty (DD),^[11] which is determined from a combination of the moves undertaken, position used, and height. The DD value is multiplied by the scores given by the judges.

To reduce the subjectivity of scoring in major meets, panels of five or seven judges are assembled; major international events such as the Olympics use seven-judge panels. For a five-judge panel, the highest and lowest scores are discarded and the middle three are summed and multiplied by the DD. For seven-judge panels, as of the 2012 London Olympics, the two highest scores and two lowest are discarded, leaving three to be summed and multiplied by the DD. (Prior to the London Olympics, the highest and lowest scores were eliminated, and the remaining five scores were multiplied by 3⁄5, to allow for comparison to five-judge panels.) The canceling of scores is used to make it difficult for a single judge to manipulate scores.

There is a general misconception about scoring and judging. In serious meets, the absolute score is somewhat meaningless. It is the relative score, not the absolute score that wins meets. Accordingly, good judging implies consistent scoring across the dives. Specifically, if a judge consistently gives low scores for all divers, or consistently gives high scores for the same divers, the judging will yield fair relative results and will cause divers to place in the correct order. However, absolute scores have significance to the individual divers. Besides the obvious instances of setting records, absolute scores are also used for rankings and qualifications for higher level meets.

In synchronised diving events, there is a panel of seven, nine, or eleven judges; two or three to mark the execution of one diver, two or three to mark the execution of the other, and the remaining three or five to judge the synchronisation. The execution judges are positioned two on each side of the pool, and they score the diver which is nearer to them. The 2012 London Olympics saw the first use of eleven judges.

The score is computed similarly to the scores from other diving events, but has been modified starting with the 2012 London Olympics for the use of the larger judging panels. Each group of judges will have the highest and lowest scores dropped, leaving the middle score for each diver's execution and the three middle scores for synchronization. The total is then weighted by 3⁄5 and multiplied by the DD. The result is that the emphasis is on the synchronization of the divers.

The synchronisation scores are based on:

• time of take-off
• height attained
• synchronisation of rotations and twists
• time of entry to the water
• forward travel from the board

The judges may also disqualify the diver for certain violations during the dive, including:

• receiving a score of 0 on all dives performed in the event
• improper equipment usage (e.g., female divers not using hair ties)

Competitive strategy

Mixed gender participants of synchronized swimming performing a dive

To win dive meets, divers create a dive list in advance of the meet. To win the meet the diver must accumulate more points than other divers. Often, simple dives with low DDs will look good to spectators but will not win meets. The competitive diver will attempt the highest DD dives possible with which they can achieve consistent, high scores. If divers are scoring 8 or 9 on most dives, it may be a sign of their extreme skill, or it may be a sign that their dive list is not competitive, and they may lose the meet to a diver with higher DDs and lower scores.

In competition, divers must submit their lists beforehand, and once past a deadline (usually when the event is announced or shortly before it begins) they cannot change their dives. If they fail to perform the dive announced, even if they physically cannot execute the dive announced or if they perform a more difficult dive, they will receive a score of zero. Under exceptional circumstances, a redive may be granted, but these are exceedingly rare (usually for very young divers just learning how to compete, or if some event outside the diver's control has caused them to be unable to perform-such as a loud noise).

In the Olympics or other highly competitive meets, many divers will have nearly the same list of dives as their competitors. The importance for divers competing at this level is not so much the DD, but how they arrange their list. Once the more difficult rounds of dives begin it is important to lead off with a confident dive to build momentum. They also tend to put a very confident dive in front of a very difficult dive to ensure that they will have a good mentality for the difficult dive. Most divers have pre-dive and post-dive rituals that help them either maintain or regain focus. Coaches also play a role in this aspect of the sport. Many divers rely on their coaches to help keep their composure during the meet. In a large meet coaches are rarely allowed on the deck to talk to their athlete so it is common to see coaches using hand gestures or body movements to communicate.

There are some American meets which will allow changes of the position of the dive even after the dive has been announced immediately before execution, but these are an exception to the rules generally observed internationally.

Generally, NCAA rules allow for dives to be changed while the diver is on the board, but the diver must request the change directly after the dive is announced. This applies especially in cases where the wrong dive is announced. If the diver pauses during his or her hurdle to ask for a change of dive, it will be declared a balk (when the diver stops mid-hurdle) and the change of dive will not be permitted.

Under FINA law, no dive may be changed after the deadline for the dive-sheet to be submitted (generally a period ranging from one hour to 24 hours, depending on the rulings made by the event organiser).

It is the diver's responsibility to ensure that the dive-sheet is filled in correctly, and also to correct the referee or announcer before the dive if they describe it incorrectly. If a dive is performed which is as submitted but not as (incorrectly) announced, it is declared failed and scores zero according to a strict reading of the FINA law. But in practice, a re-dive would usually be granted in these circumstances.

Dive positions

During the flight of the dive, one of four positions is assumed:

• straight – with no bend at the knees or hips (the hardest of the four)
• pike – with knees straight but a tight bend at the hips (the median in difficulty of the four). The open pike is a variant where the arms are reached to the side, and the legs are brought straight out with a bend in the hips.
• tuck – body folded up in a tight ball, hands holding the shins and toes pointed (the easiest of the four)
• free – indicates a twisting dive, and a combination of other positions. In the transition between two positions the diver may for example bend their legs or curve at the waist, and points will not be deducted for doing so.

These positions are referred to by the letters A, B, C and D respectively.

Additionally, some dives can be started in a flying position. The body is kept straight with the arms extended to the side, and the regular dive position is assumed at about half the dive.

Difficulty is rated according to the Degree of Difficulty of the dives. Some divers may find pike easier in a flip than tuck, and most find straight the easiest in a front/back dive, although it is still rated the most difficult because of the risk of overrotation.

An armstand dive may have a higher degree of difficulty outdoors compared to indoors as wind can destabilize the equilibrium of the diver.

Dive numbers

In competition, the dives are referred to by a schematic system of three- or four-digit numbers. The letter to indicate the position is appended to the end of the number.

The first digit of the number indicates the dive group as defined above.

For groups 1 to 4, the number consists of three digits and a letter of the alphabet. The third digit represents the number of half-somersaults. The second digit is either 0 or 1, with 0 representing a normal somersault, and 1 signifying a "flying" variation of the basic movement (i.e. the first half somersault is performed in the straight position, and then the pike or tuck shape is assumed). No flying dive has been competed at a high level competition for many years.

For example:

• 101A – forward Dive Straight
• 203C – back one-and-a-half somersaults, tuck
• 305C – reverse two-and-a-half somersaults, tuck
• 113B – flying forward one-and-a-half somersaults, pike
• 104C – front double somersaults, tuck

For Group 5, the dive number has 4 digits. The first digit indicates that it is a twisting dive. The second digit indicates the group (1–4) of the underlying movement; the third digit indicates the number of half-somersaults, and the fourth indicates the number of half-twists.

For example:

• 5211A – back dive, half twist, straight position.
• 5337D – reverse one and a half somersaults with three and a half twists, in the Free position.

For Group 6 – Armstand – the dive number has either three or four digits: Three digits for dives without twist and four for dives with twists.

In non-twisting armstand dives, the second digit indicates the direction of rotation (0 = no rotation, 1 = forward, 2 = backward, 3 = reverse, 4 = inward) and the third digit indicates the number of half-somersaults. Inward-rotating armstand dives have never been performed, and are generally regarded as physically impossible.

For example:

• 600A – armstand dive straight
• 612B – armstand forward somersault pike
• 624C – armstand back double somersault tuck

For twisting Armstand dives, the dive number again has 4 digits, but rather than beginning with the number 5, the number 6 remains as the first digit, indicating that the "twister" will be performed from an Armstand. The second digit indicates the direction of rotation – as above, the third is the number of half-somersaults, and the fourth is the number of half-twists:

e.g. 6243D – armstand back double-somersault with one and a half twists in the free position

All of these dives come with DD (degree of difficulty) this is an indication of how difficult/complex a dive is. The score that the dive receives is multiplied by the DD (also known as tariff) to give the dive a final score. Before a diver competes they must decide on a "list" this is a number of optional dives and compulsory dives. The optionals come with a DD limit. this means that a diver must select X number of dives and the combined DD limit must be no more than the limit set by the competition/organisation etc.

Until the mid-1990s the tariff was decided by the FINA diving committee, and divers could only select from the range of dives in the published tariff table. Since then, the tariff is calculated by a formula based on various factors such as the number of twist and somersaults, the height, the group etc., and divers are free to submit new combinations. This change was implemented because new dives were being invented too frequently for an annual meeting to accommodate the progress of the sport.

Trajectory

Since the parabola is symmetrical, the travel away from the board as the diver passes it is twice the amount of the forward travel at the peak of the flight. Excessive forward distance to the entry point is penalized when scoring a dive, but obviously an adequate clearance from the diving board is essential on safety grounds.

The greatest possible height that can be achieved is desirable for several reasons:

• the height attained is itself one of the factors that the judges will reward.
• a greater height gives a longer flight time and therefore more time to execute maneuvers.
• for any given clearance when passing the board, the forward travel distance to the entry point will be less for a higher trajectory.

Control of rotation

The magnitude of angular momentum remains constant throughout the dive, but since

angular momentum = rotational velocity × moment of inertia,

and the moment of inertia is larger when the body has an increased radius, the speed of rotation may be increased by moving the body into a compact shape, and reduced by opening out into a straight position.

Since the tucked shape is the most compact, it gives the most control over rotational speed, and dives in this position are easier to perform. Dives in the straight position are hardest, since there is almost no scope for altering the speed, so the angular momentum must be created at take-off with a very high degree of accuracy. (A small amount of control is available by moving the position of the arms and by a slight hollowing of the back).

The opening of the body for the entry does not stop the rotation, but merely slows it down. The vertical entry achieved by expert divers is largely an illusion created by starting the entry slightly short of vertical, so that the legs are vertical as they disappear beneath the surface. A small amount of additional tuning is available by 'entry save' techniques, whereby underwater movements of the upper body and arms against the viscosity of the water affect the position of the legs.^[18]

Twisting

A twisting dive performed from a 10-meter platform

Dives with multiple twists and somersaults are some of the most spectacular movements, as well as the most challenging to perform.

The rules state that twisting "must not be generated manifestly on take-off". Consequently, divers must use some of the somersaulting angular momentum to generate twisting movements. The physics of twisting can be explained by looking at the components of the angular momentum vector.

As the diver leaves the board, the total angular momentum vector is horizontal, pointing directly to the left for a forward dive for example. For twisting rotation to exist, it is necessary to tilt the body sideways after takeoff, so that there is now a small component of this horizontal angular momentum vector along the body's long axis. The tilt can be seen in the photo.

The tilting is done by the arms, which are outstretched to the sides just before the twist. When one arm is moved up and the other is moved down (like turning a big steering wheel), the body reacts by tilting to the side, which then begins the twisting rotation. At the completion of the required number of twist rotations, the arm motion is reversed (the steering wheel is turned back), which removes the body's tilt and stops the twisting rotation.

An alternative explanation is that the moving arms have precession torque on them which set the body into twisting rotation. Moving the arms back produces opposite torque which stops the twisting rotation.

Entry

The rules state that the body should be vertical, or nearly so, for entry. Strictly speaking, it is physically impossible to achieve a literally vertical position throughout the entry as there will inevitably still be some rotational momentum while the body is entering the water. Divers therefore attempt to create the illusion of being vertical, especially when performing rapidly rotating multiple somersault movements. For back entries, one technique is to allow the upper body to enter slightly short of vertical so that the continuing rotation leaves the final impression of the legs entering vertically. This is called "Pike save". Another is to use "knee save" movements of scooping the upper body underwater in the direction of rotation so as to counteract the rotation of the legs.

The arms must be beside the body for feet-first dives, which are typically competed only on the 1m springboard and only at fairly low levels of 3m springboard, and extended forwards in line for "head-first" dives, which are much more common competitively. It used to be common for the hands to be interlocked with the fingers extended towards the water, but a different technique has become favoured during the last few decades. Now the usual practice is for one hand to grasp the other with palms down to strike the water with a flat surface. This creates a vacuum between the hands, arms and head which, with a vertical entry, will pull down and under any splash until deep enough to have minimal effect on the surface of the water (the so-called "rip entry").

Once a diver is completely under the water they may choose to roll or scoop in the same direction their dive was rotating to pull their legs into a more vertical position. Apart from aesthetic considerations, it is important from a safety point of view that divers reinforce the habit of rolling in the direction of rotation, especially for forward and inward entries. Back injuries such as hyperextension are caused by attempting to re-surface in the opposite direction. Diving from the higher levels increases the danger and likelihood of such injuries.

Canada

The DPC logo

In Canada, elite competitive diving is regulated by DPC (Diving Plongeon Canada), although the individual provinces also have organizational bodies. The main competitive season runs from February to July, although some competitions may be held in January or December, and many divers (particularly international level athletes) will train and compete year round.

Most provincial level competitions consist of events for six age groups (Groups A, B, C, D, E, and Open) for both genders on each of the three board levels. These age groups roughly correspond to those standardized by FINA, with the addition of a youngest age group for divers 9 and younger, Group E, which does not compete nationally and does not have a tower event (although divers of this age may choose to compete in Group D). The age group Open is so called because divers of any age, including those over 18, may compete in these events, so long as their dives meet a minimum standard of difficulty.

Although Canada is internationally a fairly strong country in diving, the vast majority of Canadian high schools and universities do not have diving teams, and many Canadian divers accept athletic scholarships from American colleges.

Adult divers who are not competitive at an elite level may compete in masters diving. Typically, masters are either adults who never practiced the sport as children or teenagers, or former elite athletes who have retired but still seek a way to be involved in the sport. Many diving clubs have masters teams in addition to their primary competitive ones, and while some masters dive only for fun and fitness, there are also masters competitions, which range from the local to world championship level.

Republic of Ireland

In the Republic of Ireland facilities are limited to one operational pool at the National Aquatic Centre in Dublin. Other facilities with diving boards at the University of Limerick are undergoing staff training in an effort to start diving programmes.

United Kingdom

In the United Kingdom, diving competitions on all boards run throughout the year. National Masters' Championships are held two or three times per year.

United States

College diving

The University of Houston's CRWC Natatorium is home to the United States' largest collegiate swimming pool.

In the United States scholastic diving at the college level requires one and three meter diving. Scores from the one and three meter competition contribute to the swim team's overall meet score. College divers interested in tower diving may compete in the NCAA separate from swim team events. NCAA Divisions II and III do not usually compete platform; if a diver wishes to compete platform in college, he or she must attend a Division I school.

Each division also has rules on the number of dives in each competition. Division II schools compete with 10 dives in competition whereas Division III schools compete with 11. Division I schools only compete with 6 dives in competition. These 6 dives consist of either 5 optionals and 1 voluntary, or 6 optionals. If the meet is a 5 optional meet, then the divers will perform 1 optional from each category (Front, Back, Inward, Reverse, and Twister) and then 1 voluntary from the category of their choice. The voluntary in this type of meet is always worth a DD (Degree of Difficulty) of 2.0 even if the real DD is worth more or less on a DD sheet. In a 6 optional meet, the divers will yet again perform one dive from each category, but this time they will perform a 6th optional from the category of their choosing, which is worth its actual DD from the DD sheet.

The highest level of collegiate competition is the NCAA Division 1 Swimming and Diving Championship. Events at the championship include 1 meter springboard, 3 meter springboard, and platform, as well as various swimming individual and relay events. The points scored by swimmers and divers are combined to determine a team swimming & diving champion. To qualify for a diving event at the NCAA championships, a competitor must first finish in the top three at one of five zone championships, which are held after the various conference championship meets. A diver who scores at least 310 points on the 3 meter springboard and 300 points on the 1 meter springboard in a 6 optional meet can participate in the particular zone championship corresponding to the geographic region in which his or her school lies.

A number of colleges and universities offer scholarships to men and women who have competitive diving skills. These scholarships are usually offered to divers with age-group or club diving experience.

The NCAA limits the number of years a college student can represent any school in competitions. The limit is four years, but could be less under certain circumstances.