Special Agent Mitchell Parker tried to keep his heart rate steady. He breathed in deeply, exhaled slowly and applied techniques that were second nature to him in stressful situations, except when he was on the water. His six-foot-two frame and diving gear took up one corner of the 42-foot Duffy boat in which he sat and waited. “OK?” his teammate Ellen Beetson asked from port side. He looked over at Ellen, petite and blonde, and a divemaster. “Unlike you, I prefer my feet on land or in the air,” he said. She laughed breaking the tension. “You’ve got to agree this is beautiful,” their skipper called back as he navigated over the endless stretch of blue ocean. Mitch turned his gaze to the water streaming by him. He looked over the edge and scoped the surface of the area they were approa

