Cliff jumping is just what it says on the tin! i.e. find a suitably sized cliff, pick a soft landing area (we generally prefer water), pray to the almighty, close your eyes and launch yourself into oblivion. When taken to your first launch site you will be taught the correct techniques for jumping and entering the water correctly. The instructors will watch how you jump, and as soon as your technique is good enough, they will take you to the next level of jumping. Initial jumps generally start off at a couple of metres above water level, with the largest jumps peaking at over 25 metres in certain locations.
Anything else I should know?
You are obviously going to get wet, so make sure you bring a warm set of cloths to change into for the journey home.