ORLANDO, Fla. — It is billed as a leisurely boat tour. The shark surfaces, its fin slicing through the water. The boat's captain, armed with a grenade launcher, blasts away at the bloodthirsty monster. Nearby gas lines explode and a column of fire erupts into the blue sky. We feel the heat from the flames, hear the shark's body churning in the water. A child hides her face in the crook of her mother's arm and whimpers as chilly water sprays everyone on the boat. Of course, it isn't real. It's the "Jaws" ride at Universal Studios in Orlando, an...