Born from classic polo, water polo was initially contested with players riding floating barrels meant to resemble horses. The modern version is based on a set of rules that were introduced in Scotland in 1880. Each team was allowed seven players in the pool at once and the dimensions of the goal were fixed. Men’s water polo has been an Olympic sport since 1900 and the women’s sport was introduced 100 years later in Sydney. It has been on the Pan American Games program since 1951.
The playing field must be at least 1.8m deep x 30m long x 20m wide with a 3m x .9m goal at each end. Ropes define the playing field. Flags along the side of the pool mark the centre line, the goal line and lines that are 2 metres and 5 metres from the goal line.