[6] The Tomb of the Diver in Paestum, contains a fresco dating to around 500 to 475 BCE[7] that also shows a scene of a person diving into a pool or stream of water[7][8] from a structure.

In platform events, competitors are allowed to perform their dives on either the five, seven and a half (generally just called seven), nine, or ten meter towers.

A possible score out of ten is broken down into three points for the takeoff (meaning the hurdle), three for the flight (the actual dive), and three for the entry (how the diver hits the water), with one more available to give the judges flexibility.

The primary factors affecting the scoring are: Each dive is assigned a degree of difficulty (DD),[19] which is determined from a combination of the moves undertaken, position used, and height.

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 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.

This is frequently a source of political friction as the committees are naturally dominated by swimming officials who do not necessarily share or understand the concerns of the diving community.

Although it initially received widespread support from the diving community, the FINA requirement that international competitors had to be registered with their National Governing Body was a major factor in the abandonment of this ambition a few years later.

Since FINA refused to rescind recognition of the ASA as the British governing body for all aquatic sports including diving, this meant that the elite divers had to belong to ASA-affiliated clubs to be eligible for selection to international competition.

In the incident, 14-year-old Shawn Meneely made a "suicide dive" (holding his hands at his sides, so that his head hit the bottom first) in a private swimming pool and became a tetraplegic.

[28] Impacting with the water surface at this velocity is capable of giving a person temporary paralysis of the diaphragm,[27] a compressed spine, broken bones, or concussion.

The extreme deceleration when hitting the water flat at around 35 mph can cause severe bruising both internal and external, strains to connective tissue securing the organs, possible minor haemorrhaging to lungs and other tissues possibly resulting in a person coughing up blood,[30] a compressed spine, broken bones, or concussion.

Tom Daley has described one concussion that occurred to him "I missed my hands before the Beijing World Series and smashed my head at 35mph on to the water...".

"[29] It was commented that in 1989 a 22-year-old, who was a "...diver and a member of the Salt Lake Country Club diving team... ...climbed up on a set of towering rocks... ...about 60 feet..."[27] (18.2 metres).

In the past, the age group could compete only springboard, to discourage children from taking on the greater risks of tower diving.

Group D tower was introduced to counteract the phenomenon of coaches pushing young divers to compete in higher age categories, thus putting them at even greater risk.

Injuries that diver Tom Daley has received include "...concussions, torn triceps, broken ribs, [as well as having] coughed up blood.

"[36] In 1983, at the World University Games in Edmonton, Canada, diver Sergei Chalibashvili, aged 21, died when he was attempting a reverse 3 1/2-somersault and his head collided with the hardwood 10 metre diving platform.

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.

The center of mass of the diver follows a parabolic path in free-fall under the influence of gravity (ignoring the effects of air resistance, which are negligible at the speeds involved).

The greatest possible height that can be achieved is desirable for several reasons: The magnitude of angular momentum remains constant throughout the dive, but since 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.

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 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.

As the diver leaves the board, the total angular momentum vector is horizontal, pointing directly to the left for a forward dive for example.

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.

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.

Qualification is based on achieving minimum scores at earlier competitions in the season, although athletes who place very highly at a national championship will be automatically qualified to compete at the next.

Such competitions include the Polar Bear Invitational in Winnipeg, the Sting in Victoria, and the Alberta Provincial Championships in Edmonton or Calgary.

Masters' Diving events are normally conducted in age-groups separated by five or ten years, and attract competitors of a wide range of ages and experience (many, indeed, are newcomers to the sport); the oldest competitor in a Masters' Diving Championship was Viola Krahn, who at the age of 101 was the first person in any sport, male or female, anywhere in the world, to compete in an age-group of 100+ years in a nationally organised competition.