This United States Coast Guard USCG publication, US Coast Guard USCG Merchant Marine Medical Manual COMDTINST M16721.48 August 2019, provides guidance for evaluating the physical and medical condition of applicants for merchant mariner medical certificates. The guidance in this Manual should assist medical practitioners, the maritime industry, individual mariners, and U.S. Coast Guard personnel in evaluating an applicant’s physical and medical status to meet the requirements.