Water polo is a team water sport. The playing team consists of six field players and one goalkeeper. The winner of the game is the team that scores the most goals. Gameplay involves swimming, players passing the ball while being defended by opponents, and scoring by throwing into a net defended by a goalie. Water polo, therefore, has strong similarities to the land-based game of team handball. The frequency of 'man-up' (or 'power play') situations also draws comparisons with ice hockey.
Wikipedia [accessed 10 May 2010] http://en.wikipedia.org/wiki/Water_polo