SeaWorld’s nightly Shamu Rocks show is drawing to a close. As the celebrated killer whale arches for his final bow, several hundred yards away ten three-inch Nashiki Kamaros — Chinese-made fireworks — are hunched in their racks and ready to explode. A walkie-talkie crackles. “Ten seconds to fire.” Three pyrotechnicians huddle in a shack with their ears plugged, watching a load of explosives through a pane of glass. They are floating on a barge on Mission Bay waiting for the Nashiki Kamaros to take off. “One!” The first Nashiki rips into the night with a roar, makes a pop and sprinkles gold glitter across the sky. A prerecorded tape counts off the bursts in time to the theatrical music of Shamu’s SkySplash fireworks show, and crew member Kyle Pollitt taps a small, green light on the firing board for each shell, triggering an electrical charge. He touches 101 of these cues, launching more than 150 shells over Mission Bay in the space of five minutes. The crew, protected in the cabin, can’t see the shells bursting overhead. “Normally, one of us is out on the boat and they get to watch,” said Debbie Ludwig, operator and lead pyrotechnician at SeaWorld for the last ten years. Tonight, that person is licensed operator David Hurtado, who is securing a 600-foot perimeter around the barge to ensure boats are not hit by falling shells. Clean-up typically ensues as soon as the finale set of ten shells has blown. Pollitt isn’t sure all the cues fired, so Ludwig verifies that each mortar (the case which holds the shells) is clear. Meanwhile, Hurtado and two SeaWorld employees sweep the bay for debris. In the morning, another team on foot will check the shorelines. Ludwig, an avid scuba diver, recalls environmental protests from two summers ago. “They were concerned about chemicals falling into the water,” she said. “So I dove under the barge to check it out. It was full of life.” SeaWorld also sends divers to the bottom of the bay three times a year to clean up any debris from the falling shells: before, during and after the summer. The fourth crewmember, Travis Prater, helps gather shell casings and disconnect e-matches, the wires that carry the charge from the firing board to the shells. He’s here because he knows Pollitt, just as Ludwig came into the business 17 years ago through her husband. “It’s totally by word of mouth,” Ludwig said. “We don’t just let anybody in.” Aspiring pyrotechnicians work with an experienced operator, who decides whether they stay on and learn the trade. “If I can show them what to do here, and don’t have to repeat it again, they’re in!” Ludwig laughed. The first rule is don’t stick your head over a loaded mortar — it’s the same as staring down the barrel of a loaded gun. While a crew of four can set up for a nightly fireworks show in an hour, the July 4 weekend needs a crew of 15 people to work 10 hours to load the shells for the 20-minute shows. The crew spends two days setting up the racks that hold the mortars, and Ludwig brought in her own personal firing system for the colossal event. The July 4 show features 10 and 12-inch shells shot off from Fiesta Island — twice the size of the largest shells used for the SkySplash show. Ludwig said the audience’s reaction makes it worth all the preparation. “You take off your earphones and listen to the crowd,” Ludwig said. “It makes it all well worth it.” For a video synopsis of the preparation and launching of the July 4 weekend shows, visit http://www.youtube.com/watch?v=STy_awU18I4