A regular tennis court, 78 feet (23.77m.) long and 27 feet (8.23m.) wide.
Complete with base-lines and the side-lines and net.
The only difference being that the serving base end is actually a sunken tough mattress water-bed with a grass covering which is engineered to a irrigated underground tube system connected to the opposite serving base of the court.
As play ensues "it gets interesting" (commentator)
When a player attempts a volley within the water-bed area, the pressure when he /she lands upon the water-bed sends a wave of water to the opponent causing a ripple within their water-bed box area.
Two tennis players are now bouncing about performing rebounding under/over arm volleys in pursuit of the match.-- skinflaps, Apr 15 2004 Jump to hit the ball and give your opponent a funny bounce. [+]
Commentator:He dives! ... Player: SPLAT! *Slosh*-- Letsbuildafort, Apr 15 2004 Should work great for a football field too. They don't have to catch up with each other anymore and pile up, just generate big waves to make each other stumble and fall down.-- kbecker, Apr 15 2004 will we hear more grunting or less! drives me mad - the anticipation of waiting for the next grunt!-- po, Apr 16 2004 More grunting in the waterbed.-- FarmerJohn, Apr 16 2004 A game of doubles could be interesting.-- skinflaps, Apr 16 2004 Its about time someone came up with a tennis surface that was more interesting than grass and clay. Water, yes, thats good. Ice might be good too, with the ball occasionally freezing to the surface. Or...hey--how about hot coals?-- ldischler, Apr 16 2004 random, halfbakery