American Waterways Operators (AWO), a 350-member trade association tells members to foster a cooperative relationship with the Coast Guard and to support the mariners, wherever possible. The American Waterways Operators (AWO), the 350-member trade association representing the nation’s tugboat, towboat and barge industry recently released recommended best practices to assist both companies and mariners in navigating the U.S. Coast Guard’s mariner credentialing and medical review process.