| | ODERMUNDE | 1896 | 1942 |
| | ODIGITRA B | 1949 | 1973 |
| | ODILE R | 1930 | 1958 |
| | ODIN | 1926 | 1937 |
| | ODISSEO | 1951 | 1956 |
| | ODUPON | 1959 | 1977 |
| | ODYSSEUS | 1918 | 1931 |
| | ODYSSEUS | 1922 | 1927 |
| | ODYSSEUS | 1954 | 1993 |
| | OEDENRODE | 1917 | 1917 |
| | OENGARAN | 1883 | 1894 |
| | OEVELGONNE | 1888 | 1888 |
| | OFFSHORE I | 2000 | 2000 |
| | OFFSHORE II | 2001 | 2001 |
| | OFIR | 1920 | 1957 |
| | OGAN | 1902 | 1902 |
| | OGAN | 1948 | 1962 |
| | OGAN I | 1902 | 1905 |
| | OGAN II | 1905 | 1905 |
| | OGRE | 1918 | 1939 |
| | OGURA MARU 3 | 1916 | 1928 |
| | OHIO | 1899 | 1899 |
| | OHM | 1941 | 1941 |
| | OIG I | 1961 | 1995 |
| | OIL DRAGON | 1944 | 1973 |
| | OISE | 1926 | 1926 |
| | OISTEIN | 1910 | 1916 |
| | OISTERWYK | 1920 | 1924 |