who are their predators?
Juveniles are preyed upon by larger sharks such as bull sharks and adults have no major predators except for killer whales.
Great hammerhead
 Juveniles are preyed upon by larger sharks such as bull sharks ("Carcharhinus leucas"), while adults have no major predators except for killer whales, who hunt hammerheads of any age. 
what is 'great hammerhead'? The largest species of hammerhead shark. what is the length of these largest species? UNANSWERABLE in which specific areas are they commonly found? Generally in tropical waters between the latitudes of 40°N and 37°S. The places include  North Carolina to Uruguay,  Morocco to Senegal, the Mediterranean Sea, along the rim of the Indian Ocean , and in the Pacific Ocean. what do these large species eat? Crabs, lobsters, squid, octopus,tarpon, sardines, sea catfishes, toadfish, porgies, grunts, jacks, croakers, groupers, flatfishes, boxfishes, and porcupine fishes, and smaller sharks such as smoothhounds.
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Great hammerhead [SEP] Biology and ecology
The great hammerhead is a solitary, nomadic predator that tends to be given a wide berth by other reef sharks. If confronted, they may respond with an agonistic display: dropping their pectoral fins and swimming in a stiff or jerky fashion. Juveniles are preyed upon by larger sharks such as bull sharks ("Carcharhinus leucas"), while adults have no major predators except for killer whales, who hunt hammerheads of any age. Yellow jacks ("Carangoides bartholomaei") have been seen rubbing themselves against the hammerhead's flanks, possibly to rid themselves of parasites. Schools of pilot fish ("Naucrates ductor") sometimes accompany the great hammerhead.