Cmdr. Petta enlisted in the U.S. Navy in 1992 and served 10 years as a sonar technician before separating to attend the U.S. Coast Guard Officer Candidate School. In the U.S. Coast Guard, he has served in engineering, legal and logistics billets. He is now a military professor and the associate director of maritime operations with the Stockton Center of International Law at the U.S. Naval War College.