It is evening at San Benedicto Island , Mexico , October 1989 . I am hunting adjacent to a rocky underwater pinnacle , its tip reaching just 10 feet short of the surface , its sides plummeting to the ocean floor 300 feet below . This subsurface rock is a giant fish magnet . Large oceanic predators are attracted by clouds of bait fish seeking both food in the passing currents , and refuge in the pinnacle ’ s crevices and caves . It is evening and a glance toward the horizon reveals just a finger ’ s width of sky under the rapidly sinking sun . Except for a small area of beautiful penetrating golden light from the sun , the deep blue water is now black .
As I make my way , swimming up-current , schooling hammerhead sharks circle just 50 feet below . I have never seen hammerhead sharks in this schooling mode show any aggression toward a diver , nor have I seen them attack a speared fish . Nevertheless , their presence , along with the darkening water ,
heightens my awareness .
This is a wild time of day ! Just a few minutes more and nightfall will force me from the water .
The always nervous bait fish are now frantic . Several times a minute I sense distant bait fish being attacked . Their escaping tails , beating as one , emanate an eerie , deeply pitched thundering sound ; it strikes me , reverberating in my chest ……
BOOM …… BOOM ………… BOOM .
I know the tuna are near ; I feel them close by . Suddenly I hear , “ Tuna !… I ’ m on !” I look up to see the crew from our mother boat , the Ambar III , dispatch the chase skiff to aid my fellow diver , heading out to sea , pursuing his disappearing floats .
Once again I dive into the ever darkening water and orient into the current . My heart is pounding . A perfect circle appears at the limit of visibility , now another and another ;