An investigation of 30 recorded deaths in sport diving in California in 1970 gave evidence of equipment failure in two, a failure of the victims' judgment or training in 13, and a failure of rescue attempts in four instances. In three histories no cause could be found. Factors associated with the deaths are reported. In the same period there were recorded in the state 171 drownings in home pools out of a total of 712 drownings in water sports.