The following classification societies have been appointed as Recognized Organizations (ROs) and Recognized Security Organizations (RSOs) with full authorisation to carry out statutory surveys/audits, plan approvals, and issue international convention certificates for and on behalf of the Nauru Maritime Administration.

• American Bureau of Shipping (ABS)
• Bulgarian Register of Shipping (BRS)
• Bureau Veritas (BV)
• China Classification Society (CCS)
• DNV (DNV)
• Indian Register of Shipping (IRCLASS)
• International Ship Classification (ISC)
• Korean Register of Shipping (KR)
• Lloyd's Register (LR)
• Nippon Kaiji Kyokai (NK)
• Polish Register of Shipping (PRS)
• Registro Italiano Navale (RINA)
• Russian Maritime Register of Shipping (RS)