Water polo matches are divided into four quarters of seven minutes (actual playing time) with teams exchanging ends after each quarter.
Teams comprise seven players in the water plus up to six substitutes. Substitutions may be made after each period, when a goal has been scored, if a player has been excluded by the referee or by injury and during play by the team in possession of the ball.
Officials include two referees plus timekeepers and scorekeepers.
Catching, passing and shooting with the ball must be one handed (with the exception of the goalkeeper). Standing or jumping are not allowed.
Holding or sinking of an opposing player is not allowed unless that player is holding the ball at the time. Fouls are classified as ordinary or major (three major fouls will cause a player to be excluded for the remainder of the match).
Possession of the ball (football sized but lighter) by each team is limited to 35 seconds.
