A real-life legend of Zihuatanejo, Oliverio Maciel Díaz was born Nov. 12, 1924 here in Zihuatanejo. By the age of 10 he was fishing and free diving, spending most of his time on and in the water. Friends from that era say he was a true sireno (merman): half man and half fish. By the time the decade of the 50's rolled around, thanks to the introduction of the "aqualung" to the area by don Carlos Barnard in 1949, Oliverio had become the most proficient local diver, earning the nickname "El Rey Nep...