Water polo is fast, furious and easy to understand, with players needing to combine skill and accuracy with endurance.
Lisa Knights, BBC Sport
"Anything goes under the water and players compete to gain whatever advantage they can. For Team GB, the women should fight for the bronze medal. They are led by Sam Leighton, who sets a great example to her team. For the men, Craig Figes's side have been given an incredibly hard draw for the group stage with heavyweights Serbia and Hungary in there with them. London 2012 will be the swansong for Hungary's Tamas Kasas, who is looking to end his Olympic career with a fourth successive gold medal. Brenda Villa is tiny by water polo standards but she'll be hoping to inspire the United States' women to success."
For Great Britain, there has been nothing to cheer since winning four of the first five Olympic tournaments and the country has not even qualified since 1956.
Host nation status means both men and women will have teams at London, although medals are unlikely to be on the cards.
Hungary are the sport's most successful Olympic team with 15 medals, including nine golds, and have won the last three men's titles. However, they are yet to win a medal in the women's event, which was introduced at the 2000 Games in Sydney.
Russia (previously the Soviet Union), Serbia (previously Yugoslavia), Italy and the USA have also performed consistently well down the years.
Why is it good for you?
Water polo combines the shooting skills of handball, the ball-handling skills of basketball or netball, and the speed and stamina of swimming.
Players can swim up three miles at a high tempo in the course of a match. This means you can burn approximately 465 calories during a game, making it an excellent way to lose body fat.
As it is a team game, water polo is an excellent way to develop communication skills and learn to work effectively with other people.
Clubs also offer a variety of social events beyond simply playing the sport.
Water polo works many of the muscle groups in the body. The leg muscles are in constant motion as players keep themselves afloat, while the ball-throwing action strengthens arm muscles.
The effort of intensive swimming combined with fighting for possession helps boost cardiovascular fitness and lower blood pressure.
For those looking to take part,
there are more than 300 water polo clubs in the United Kingdom. People in England, Wales and Scotland can visit the
British Swimming team sports page
for details of where you can play.
websites contains information for where people in Northern Ireland can find their nearest club.
Can you compete?
Get your performance under pressure analysed in just 20 minutes by four-time Olympic gold medallist Michael Johnson
Further details about training schemes and events can be found on the
Amateur Swimming Association,
Water polo clubs provide balls, nets, referees and coaches to members. For beginners, all you will need is a swimming suit or swimming trunks, and a swimming cap.
Many clubs offer mini water polo sessions for children aged eight to 11. This activity teaches the fundamentals of aquatics and the sport as a whole.
British Swimming is working with the BBC to get the UK into the pool in a celebration of swimming events called the
A wide range of
including competitive races, swimming lessons and aqua aerobics, are being put on in swimming pools throughout the country.
Sign up to British Swimming's
to be sent details of the latest events and use their
to find out where you can get started.
More on the British Swimming website
Want to get involved with sport in your local community? Why not Join In ?
'Join In Local Sport'
aims to get as many people as possible to turn up and take part in activities at their local sports facilities on
18/19 August, 2012
- the first weekend between the Olympic and Paralympic Games.
The aim of the initiative is for every sports club and community group in the UK to put on a special event in a bid to encourage more people to get involved as members, supporters or volunteers.
More than 4,000 local sports clubs will be opening their doors to host events and show people just how they can get involved.
As well as tips on playing sport there will be information on coaching, supporting and how to help out.
Find an event
The competition format at London 2012
- From Sunday 29 July to Sunday 12 August, 260 athletes (156 men, 104 women) will compete at the Water Polo Arena.
- Eight women's teams play in one group while 12 men's teams are divided into two groups.
- The top four men's teams from each group advance to the quarter-finals, before semi-finals and a final play-off for the gold.
- The top four women's teams from the preliminary group advance to the quarter-finals.
- In both the men's and women's competitions, the semi-final winners play in the final for the gold medal and the semi-final losers will contest the bronze medal in a third-place play-off.
More on the London 2012 website
The rules at London 2012
Each nation has a 13-man squad, with seven allowed in the pool at any one time. The number of substitutions are unlimited.
Matches consist of four periods, each of them eight minutes long. A team has just 30 seconds to attempt to score before the ball is returned to the opposition.
Great Olympic moment
Hungary came from 7-5 down to beat Serbia 8-7 in the Athens 2004 final, with Gergely Kiss scoring the winning goal
Whenever the referee whistles, the clock and play both stop.
At the start of each period, players line up on their goal line and the ball is released from a special float in the centre of the pool.
Only the goalkeeper can touch or hold the ball with both hands, but a goal can be scored by any part of the body apart from the clenched fist.
Players are not allowed to touch the sides or the bottom of the pool during play.
In each group stage match, two points are awarded for a win, one for a draw and none for a defeat.
If, at the end of a knockout match, the score is tied, two further three-minute periods will be played. A penalty shoot-out of five penalties per team will take place if no winner emerges.
If the match still remains tied, a sudden-death shoot-out will take place.
More on the Team GB website
Ones to watch
Both the Team GB men's and women's sides will have their work cut out against the powerhouses of world water polo.
The women, already through to the quarter-finals as the group stage is used to determine who plays who in the last eight, will struggle to go further. The men will do well to reach the quarter-finals, with four teams set to bow out after their group games.
Serbia are men's World League, World Cup and European champions, but Italy beat them in the final of the World Championships last year. Croatia and Montenegro are also strong, while Hungary are looking for a fourth straight gold.
The women's event is wide open, with USA, Italy, Greece and China among the contenders for the title.
So called because in its earliest days players rode on floating barrels that resembled mock horses, and swung at the ball with mallet-like sticks, water polo was developed in Europe and the United States as two differing sports.
The modern form of the game is based on the European version and made its Olympic debut at the Paris Games in 1900 when Great Britain won gold.
Did you know?
Wedgies - where players pull up an opponent's swimming costume to cause eye-watering discomfort - are so commonplace in the women's game that some teams, including the Spanish, have taken to giving themselves wedgies before matches in order to prevent them during play
Their superiority over Belgium in the final was such that they limited the amount of shots they took to spare their opponents' embarrassment.
The early version of the sport bore a key difference to the one we now know - swimming was not necessary.
Instead, those first Olympic medals were contested in pools only deep enough for a spot of advanced wading. As a result many of the players could not actually swim.
During the 1920s though, games were switched to larger, deeper pools. Swimming became a prerequisite and the sport advanced from little more than a holiday pastime to a skilled and physically demanding sport.
It was not included in 1904 but has appeared at each subsequent edition of the Games, with the women's event introduced in 2000.
More on the IOC website