They change ends between the two periods. If the score remains tied after that, they play a third, sudden-death extra period with no time limit. Field of play Water polo at the Sydney 2000 Olympic Games will be played in a common 50-metre swimming pool, but the water must be at least two metres deep throughout meaning players swim or tread water the whole time. Floating ropes will mark off the field of play, 30m by 20m for men and 25m by 17m for women. Coloured buoys mark various imaginary lines across the playing area.
White buoys mark the two goal lines and the half-distance line.
Red buoys indicate the two-metre lines near each goal line. Red exclusion areas are set out at each end, behind the goal lines and two metres in from the corners opposite the officials' table. The areas mark where players enter and leave the field of play. Excluded players wait in the exclusion areas for the signal to re-enter. Two goals, three metres wide and 90 centimetres high, float on the water.