Risk is measured. Safety is judged.
Safety is the personal or societal acceptance of a given risk.
Risk is a measured quantity. Risk is the product of the probability of something happening and the severity of harm when it does happen. All events in skydiving could be assigned some risk value, based on the definition just given. The risk value should be based on data collected over many years or test drops. In essence, the risk value for an event should be based on a large set of measurements and observations.