Brought to you by sportsister.com

Jargon buster

Ball under: When a player fouls by taking or holding the ball underwater as an opponent tackles them.

Swim-off: This marks the start of each period. Both teams race for the ball in the centre of the field of play.

Exclusion area: Excluded players must wait in this area outside the field of play before they are allowed to continue playing.

Free throw: A free throw is given if the ball crosses the sideline or a player commits a foul that doesn’t warrant a penalty throw.

Dry pass: A pass designed to be caught before the ball hits the water.

Eggbeater: This powerful way to tread water is also used in synchronised swimming.

Basic rules

There are seven players in a team; a goalkeeper and six ‘outfield’ players. Games at London 2012 will take place in 25m long, 2m deep pitches across four eight-minute periods.

The goals at either end, which sit on top of the water, are 3m wide and 90cm high and the aim is to score as many goals as possible in the opponent’s net. Each team has 30 seconds to score before the ball passes to the opposition.

Players may not touch the bottom or side of the pool during a match and only the goalkeeper is permitted to have both hands on the ball at the same time.

If a major foul is committed that player is temporarily excluded for 20 seconds. If three major fouls are committed by any one player in a game they are sent off for the remainder of the match.