Petty Officer 3rd Class Britan Nagel, a marine safety technician from the Marine Safety Detachment in Sturgeon Bay, Wis., responds to a reported oil sheen in the Sturgeon Bay ship canal July 30, 2013. Coast Guard MSTs play an essential role in enforcing regulations for the safety of the marine environment and the security of the port. (U.S. Coast Guard photo by Petty Officer 1st Class Brian O'Neil)