These kinds of risk calculations are perhaps useful for insurance companies, but for individuals doing a "dangerous" sports there is more to the risk than merel

These kinds of risk calculations are perhaps useful for insurance companies, but for individuals doing a "dangerous" sports there is more to the risk than merely probability. In particular, with something like cave diving and mountain climbing the "bad" outcome is going to be death of the individual or their friends and it will likely be the result of a series of bad decisions under stress (each of which makes the situation more dire) rather than an exceedingly rare multiple systems failure.