U.S. Navy Chief Special Boat Operator Jeremy Gomez, left, a Basic Crewman Training (BCT) instructor, demonstrates a combat ascent to a student at Naval Amphibious Base Coronado, Coronado, Calif., Aug. 6, 2008. Students performed hull inspections on the rigid-hulled inflatable boat, looking for simulated cracks and holes while swimming with held breath. BCT is the first phase in the Special Warfare Combatant-craft Crewman (SWCC) training pipeline. SWCCs operate and maintain the Navy's state-of-the-art, high-speed boats used in support of SEALs in special operations missions worldwide.