Navy Diver 3rd Class Tom Chlebda of Mobile Diving and Salvage Unit (MDSU) 2 splashes into the water to begin a diving operation. MDSU 2 is conducting a gross survey diving operation with the help of the Beaufort County Sheriff's Office to search for people and vehicles following a simulated bridge collapse in South Carolina during Ardent Sentry 2013. Exercise Ardent Sentry is an annual NORAD and U.S. Northern Command (USNORTHCOM) exercise focused on Defense Support of Civil Authorities (DSCA) scenarios to support civil authorities, when requested, with military capabilities to save lives, prevent human suffering, and mitigate great property damage. (U.S. Navy photo by Mass Communication Specialist 1st Class Dustin Q. Diaz/Released)