We were on an assignment to video baitball activity and another unsuccessful day was drawing to a close as our small inflatable skimmed across the smooth leeward waters of Cocos Island. Dramatic large animal footage had been logged during our sojourn aboard the Okeanos Aggressor, but our assignment was a baitball. On that front, we had nothing, nada, big zero, not happening, not gonna get a job from Paramount again. Rounding the pinnacle that defines Chatham Bay, we noticed a large group of squawking boobies clambering above the water. Our multiple failures had produced a sense of helplessness, and I remained draped over the dinghy's pontoon. My partner on the project, Jay Ireland, scuttled through his now disorganized gear for his mask while motioning our driver toward the airborne beacon. Jay poked his head into the water for a few seconds, withdrew and stated, ''Let's go. This is it.'' Moments later we back-rolled into a caldron of feeding activity unlike anything I had ever seen before. Perched safely in front of my computer in California, the mystery of baitball activity had made this assignment seem irresistible; now it's unknown nature was unnerving.After checking my gear, I headed toward the center of the ball where Jay was already positioned. Intently viewing the chaos through his monitor, he failed to see a 7-foot silky shark bank sharply and slam into his bright yellow tank. Briefly stunned, he recovered in time to retrieve the video housing that had been jarred from his hands. The baitball feeding frenzy was simultaneously fascinating, beautiful, surreal, melodic and terrifying. The cameras we hid behind gave us a false sense of security. Soon we were pushing closer and closer into the blind core of activity. When the tape ran out, reality set in. I was in the middle of an underwater maelstrom. Baitfish pulsated tightly around me, closely followed by sharks, rainbow runners and tuna. I quickly back-pedaled to the periphery and began my ascent. Several sharks surrounded me as I reached the surface. Briskly rotating like a bobbing top, I prayed for our inflatable to arrive. The welcome arrival of the boat presented a final challenge. Keeping my eyes on the circling sharks, I handed my camera and gear to the driver before flopping myself awkwardly into the dinghy. It was time to reload and get back in the water. For more information about diving Cocos Island from the Okeanos Aggressor, click on the home page below. For general information about traveling to Costa Rica, click on the home page below.