Water polo is divided up into four quarters of 8 minutes of actual playing time per quarter, i.e. the clock stops for fouls, time-outs, injuries etc.. This means a total playing time of 32 minutes. However, a game normally lasts about one hour.
A water polo team consists of 13 players, at least one of which will be a goalkeeper. Seven players may be in the water at any one time, one of which will be a goalkeeper.
Players must not stand or touch the bottom of the pool which along with the considerable holding and pushing that occurs, means that a great deal of stamina is required.
Substitutions of one player for another are frequently made for that reason. This may be done between periods, following a goal, during a time-out, or during the game at the re-entry area.
Players wear caps, usually white for the home team and blue for the visitors, with red caps reserved for goalkeepers. These incorporate numbers one to thirteen, and include ear-guards and usually some shock absorption to the forehead.
The primary aim of the game is to get the ball into your opposition's goal as many times as possible. One point is awarded for every goal scored.
Water polo is a physical sport where players will push against, and hold each other in an attempt to gain possession of the ball. Intentionally kicking or striking another player, holding them back, sinking them, holding them under, or swimming on their back would be foul play leading to a ‘major foul’ exclusion.
Any player committing a major foul will be excluded for 20 seconds, leaving the pool at the re-entry point without interfering with play. The player may return before the 20 second period has expired if a goal is scored, or his/her team regains possession.
Any player committing three major fouls during a match is expelled for the remainder of the game.
Each team is permitted possession of the ball for a maximum of 30 seconds before releasing a shot at goal. In default of this, possession passes to the other team.
Referees, normally two, take charge of the game to assure fair play. They are positioned one on each side of the pool, and their responsibilities change with possession and direction of play. As with other sports, the referees' decisions are final.
If an ordinary foul is committed, a free throw will be awarded from where it occurred or further back in the territory of the team to which the the free throw has been awarded. This must be taken immediately, and opposition players must not interfere until the ball has been released. A free throw can be played to oneself, but if so, no shot can be made on goal unless immediately from outside the five metre line.