The game has two halve. Each half is fifteen minutes. In the middle, the game stops and the players have a break for four minutes. There are two teams. One team usually wears white and the other team wears blue or black. Each team has eleven players. But your team can’t have eleven players in the water at the same time. Only six people from each team can be in the water. It’s very difficult to swim fast under water for a long time.So the other five players are substitutes they go in and play when the other players get tired.