The original South Indian method ...

  1. Strip off any loose fibers from the coconut.
  2. Wet the coconut thoroughly
  3. Find a flat hard surface and a bowl to put the coconut water in.
  4. The crown of the coconut has three black spots spaced at 120 degrees. There are also three visible ridges between the spots.
  5. Slam the coconut on the hard surface, aiming for the ridges. Do not hit too hard. It may take several blows to crack.
  6. When a crack appears, allow the water to drain into the bowl.
  7. Finally separate the two halves of the coconut completely.
  8. Slurp .. gulp the coconut water.

If it wasn't yummy then the coconut's not fresh.