BOSTON - Navy Supervisor of Salvage and Diving crews aboard two boom handling boats work to pull a high speed Current Buster System in Boston Harbor during a simulated oil spill for the 2010 Spill of National Significance exercise, Wed., March 24, 2010. The SONS exercise, which simulates a rare catastrophic spill, provides an opportunity for emergency responders from more than 50 different agencies to practice a joint response to a major spill. Coast Guard photo by Petty Officer 3rd Class Connie Terrell.