Diving is the sport of jumping or falling into water from a platform or springboard, usually while performing acrobatics. Diving is an internationally recognized sport that is part of the Olympic Games. In addition, unstructured and non-competitive diving is a recreational pastime.
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. The 1904 book Swimming by Ralph Thomas notes English reports of plunging records dating back to at least 1865. 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).
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.

Competitive diving:

Most diving competitions consist of three disciplines: 1 m and 3 m springboards, and the platform. Competitive athletes are divided by gender, and often by age group. 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. In major diving meets, including the Olympic Games and the World Championships, platform diving is from the 10 meter height.
Divers have to perform a set number of dives according to established requirements, including somersaults and twists. Divers are judged on whether and how well they completed all aspects of the dive, the conformance of their body to the requirements of the dive, and the amount of splash created by their entry to the water. 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 raw score is multiplied by a degree of difficulty factor, derived from the number and combination of movements attempted. The diver with the highest total score after a sequence of dives is declared the winner.

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.

Diving is also popular as a non-competitive activity. Such diving usually emphasizes the airborne experience, and the height of the dive, but does not emphasize what goes on once the diver enters the water. The ability to dive underwater can be a useful emergency skill, and is an important part of watersport and navy safety training. Entering water from a height is an enjoyable leisure activity, as is underwater swimming.
Such non-competitive diving can occur indoors and outdoors. Outdoor diving typically takes place from cliffs or other rock formations either into fresh or salt water. However, man-made diving platforms are sometimes constructed in popular swimming destinations. Outdoor diving requires knowledge of the water depth and currents as conditions can be dangerous. On occasion, the diver will inadvertently belly flop, entering the water horizontally or nearly so. The diver typically displaces a larger than usual amount of water.