The width of the field of play shall be 20m and the goal lines holds the free floating goals in position with 2 goal lines each side and for the wall hanged goal 1 goal line each side.
On one side - close to the field line - of the water polo goal there is the red re-entry area - red box - demarcation of 2 meters.
Goal lines are affixed in pool wall and made to measure and according to pool width. Most often field of play is centred in pool and goal lines made from 100mm/4" material complete with take-up reel and tension spring.
When using 8 goal line, for are with the red re-entry markings and 4 are all white.