One in five British children is unable to swim 25 metres by the age of 11.

Swimming is one of the best forms of exercise. Because the density of the human body is similar to that of water, the body is supported by the water and less stress is therefore placed on bones and joints.

At the time of the 2008 Olympics, Great Britain possessed 24 Olympic length 50m pools. Or, put another way, one 50m pool for every 2.5 million people.

Rebecca Adlington became the first British woman to win an Olympic swimming gold medal for 48 years when she claimed the 400m freestyle title at the 2008 Beijing Games. Adlington then proceeded to win her second gold medal when she smashed Janet Evans’s 19-year-old world record to romp to victory in the 800m freestyle final. No other British woman has ever won two Olympic swimming gold medals.

Cassie Patten, the Be Number 1 swimmer, finished eighth in that 800m freestyle final before ducking under the lane ropes to give Adlington a hug. Patten said: “If the Queen is watching, this girl should be made a dame - Dame Rebecca Adlington. Two Olympic golds is awesome. She’s my best mate, so I’m allowed to say that.”

Britain, with six swimming medals (two gold, two silver and two bronze) finished third behind USA and Australia in the swimming medals table at the 2008 Olympics. That compared favourably with the 2004 Athens Games, where Britain won only two bronze medals to finish in 18th position in the swimming table - 10 places below Zimbabwe and one above Trinidad & Tobago.

Overall, Britain have garnered 65 Olympic swimming medals, with 35 of them being claimed by men and 30 by women. Only two countries have won more than 100 Olympic swimming medals: USA, who have claimed 493, and Australia (176).

Adrian Moorhouse was the last British man to win an Olympic swimming gold medal. He triumphed in the 100m breaststroke in 1988.

Swimming has been an integral sport at the Olympics since the first modern Games of 1896, when four events were held in the Bay of Zea, near Athens. The four events in question were 100m freestyle, 500m freestyle, 1,200m freestyle…and a 100m freestyle competition for Greek sailors. Yes, really!

The first Olympic swimming champion was Alfred Hajos, a 19-year-old Hungarian, who won the 100m freestyle in the chilly waters of the Mediterranean. Women’s swimming events were introduced to the Olympics in 1912.

“My will to live completely overcame my desire to win,“ said Hajos after he had overcome heavy sea surf and a water temperature of 55° F to win the 1,200m freestyle at those same Athens Olympics. He won by being the first swimmer to reach shore after a boat had left the competitors in the none-too-inviting waters of the Mediterranean.

Swimming events at the 1900 Paris Olympics took place in the River Seine. Among the unusual events on the Olympic swimming roster that year were underwater swimming and a 200m obstacle race.

A pool was first used for Olympic swimming at the London Games of 1908, the same year that FINA, the sport’s governing body, was founded. A 100-metre pool was constructed inside the athletics track. The 1924 Paris Olympics were the first to use a 50-metre pool with marked lanes.

Michael Phelps, the American swimmer, won eight gold medals at the 2008 Olympics, the most ever gained by one person at a single Games. Phelps has won an overall total of 14 Olympic golds, more than any other Olympian in any sport.

As well as winning seven gold medals at the 1972 Munich Olympics, American swimmer Mark Spitz won four medals (two gold, one silver, one bronze) at the 1968 Games in Mexico City.

Anthony Nesty of Surinam became the first black swimmer to win an Olympic gold medal when he lifted the 100m butterfly title at the 1988 Seoul Games.

Open-water swimming, as defined by FINA, is any competition that takes place in rivers, lakes or oceans. The men’s and women’s 10km open-water events were added to the Olympic swimming programme for the 2008 Beijing Games.

The Shropshire-born Captain Matthew Webb became, in 1875, the first person to swim the English Channel. Since then, more than 900 different swimmers have accomplished the feat.

Open-water swimmers have to wear a microchip transponder on each wrist throughout the race. If a competitor loses a transponder, a replacement can be issued, but he is disqualified if he finishes the race without one. Swimmers can also be disqualified for making intentional contact with a fellow competitor.

No more than two participants per country were permitted to compete in each of the 10km marathon events at the 2008 Beijing Olympics. Be Number 1 athletes David Davies and Cassie Patten won silver and bronze, respectively, in their disciplines while Keri-Anne Payne’s second-place finish in the women’s race meant that Britain claimed three of the six open-water swimming medals in China.

Elephants, which use their trunks as natural snorkels, are capable of swimming 20 miles a day, .

Tuna generally swim at a steady speed of about 10 miles per hour and they rarely stop…..which means that a 15-year-old tuna will have probably swum more than 1,000,000 miles. They have been known to swim at speeds of more than 50 miles per hour.

Divers in the 14th century made goggles from polished, clear tortoise shell. The first rubber goggles, which had heavy glass lenses, were invented in the 1930s.