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 Neptuno", and for the next 4 decades he was sought by the rich, the powerful and the famous to take them diving. He also collaborated with Jacques Yves Cousteau.

Oliverio Maciel Díaz Oliverio Maciel Díaz Oliverio eventually became the most sought-after expert who best knew the waters of the entire Costa Grande. He had roles in numerous movies including "La Tintorera", "Ciclón", "El Triángulo de las Bermudas", "El Niño y el Tiburón", "Beyond the Reef", "Las Pirañas Aman en Cuaresma", "Historias del Rey Neptuno", and "El Día de los Asesinos". There was even a character dedicated to him in the popular comic "Chanoc".