I've always wanted to go cliff diving, but it seems so dangerous. People have told me that if you fall high enough the water can feel like concrete. Also, if the water is too shallow, you could potentially hit the ground and get injured. The speed that you enter the water can lead to injury as well. You can reach speeds up to 25 mph when jumping from only 20 feet. jumping into water from a high point can disorient you when you land in the water. depending on how deep the water is, this can be dangerous and potentially lead to drowning. Also, if you injure yourself during the dive, it could be hard to swim to the surface. Needless to say, there is a lot of danger involved in cliff diving. 

My research tells me that good form goes a long way. It is much easier to break the surface of the water if you are in a pencil shape compared to a cannon ball. The reason that a pencil dive is better than a cannon ball in terms of diving is because of work. In both the pencil and cannon ball case, the object is being acted upon by gravity, meaning that it enters the water with the same amount of force. When the object makes contact with the water, the water is moved a displacement in order to make room for the object in the new median. In a pencil dive, there is less surface area, meaning that the water displaces less. In a cannon ball, there is more surface area meaning that the water displaces more. The force of gravity does more work on the water during a cannon ball dive compared to a pencil dive. Also, mechanical energy is lost from the system when the object hits the water because the of the work done by gravity to break the surface. if both the cannon ball dive and the pencil dive have the same total energy, the cannon ball dive loses more mechanical energy because it uses more energy to do work on the water. This is why the pencil dive is able to go deeper.