 | Ocean Tankers Holding Ltd., Nicosia | |
 | Ocean7 Projects A.p.S., Kolding | |
 | Oceania Cruises GmbH, Surberg | |
 | Oceanwide Expeditions B.V., Vlissingen | |
 | Odfjell Tankers AS, Bergen | |
 | Reederei Claus-Peter Offen GmbH & Co.KG, Hamburg | |
 | Reederei Jürgen Ohle KG, Drochtersen | |
 | Ohlrogge Schiffahrts KG, Brake | |
 | Oldendorff Carriers GmbH & Co.KG, Lübeck | |
 | Fred Olsen Cruise Lines Ltd., Ipswich | |
 | Olympic Shipping AS, Fosnavaag | |
 | Olympic Shipping & Management S.A., Athens | |
 | Omega Navigation Enterprises Inc., Piraeus | |
 | OMI Marine Services LLC | |
 | Orient Overseas Container Line Ltd., Hong Kong | |
 | Oost Atlantic Line B.V., Pernis | |
 | Oldenburg-Portugiesische Dampfschiffs-Rhederei GmbH & Co.KG, Hamburg | |
 | Orient Marine Co.Ltd., Tokyo | |
 | Orion Bulkers GmbH & Co.KG, Hamburg | |
 | OSG Shipmanagement Ltd. | |
 | Oslo Bulk Shipping AS, Oslo | |
 | Österströms Rederi AB, Norrköpping | |
 | Ost-West Handel Schiffahrts GmbH & Co.KG, Bremen | |
 | Overseas Maritime Carriers S.A. |