| Ship Name | Ship Type | Notes |
| I Index | Built: 1908 Tonnage ** | |
| Ida | Ketch | Built: 1884 Tonnage 29 |
| Ida | Cutter | Built: 1896 Tonnage 10 |
| Ida | Steamship | Built: 1919 Tonnage: 5,677 |
| Ida | Scow | Built 1885 Tonnage ** |
| Ida | Steamer | Built: 1875 Tonnage: 12 tons |
| I Dont Know | Schooner | Built: 1843 Tonnage ** |
| Ihumata | Built: 1911 Tonnage: 1,155 | |
| Ika | Built: 1907 Tonnage ** | |
| Ikatere | Built: 1940 Tonnage 8 | |
| Ilma | Built 1885 Tonnage 345 1911 purchased from E. Pike, Sydney, 1937 scuttled. | |
| Imp | Schooner | Built: 1842 Tonnage ** |
| Imperial | Ferry | Built **** Tonnage ** |
| Ina | Steamship | Built: 1919 Tonnage: 5,677 |
| Inaha | Steamer | Built: 1875 Tonnage: 12 |
| Inaha | Steamer | Built: 1875 Tonnage: 12 |
| Inaha | Built **** Tonnage ** | |
| Inca | Built **** Tonnage ** | |
| Inconstant | Built **** Tonnage ** | |
| Industry | Schooner | Built: 1858 Tonnage 23 |
| Independant | Lugger | Built: 1847 Tonnage ** |
| India | Barque | Built: 1882 Tonnage ** |
| Industry | Schooner | Built: 1842 Tonnage ** |
| Industry | Steamship | Built **** Tonnage: 3,000 |
| Inez Dean | Ketch | Built: 1905 Tonnage 12 |
| Inga | Steamship | Built: 1904 Tonnage: 948 |
| Inglis | Steamship | Built **** Tonnage ** |
| Ino | Steamer | Built: 1847 Tonnage 23 |
| Ino | Fore and aft | Built **** Tonnage 28 |
| Invercargill | Steamer | Built: 1885 Tonnage 123 |
| Invincible | Barque | Built: 1853 Tonnage ** |
| Iona | Coastal vessel | Built: 1923 Tonnage: 251 |
| Iona | Ferry | Built **** Tonnage ** |
| Iona | Steamer | Built: 1875 Tonnage 158 NSS |
| Iona | Paddle Steamer | Built: 1878 Tonnage 60 |
| Iona | Schooner | Built **** Tonnage 78 |
| Iona | Schooner | Built **** Tonnage 159 |
| Iorangi | Cutter | Built: 1902 Tonnage 10 |
| Ira | Schooner | Built: 1842 Tonnage ** |
| Ira | Schooner | Built: 1849 Tonnage ** |
| Iran | Built **** Tonnage ** | |
| Iranui | Tug | Built **** Tonnage ** |
| Iranui | Built: 1924 Tonnage: 19 | |
| Irene | Schooner | Built: 1889 Tonnage 37 |
| Irene | Scow | Built 1889 Tonnage ** |
| Iris | Cutter | Built: 1875 Tonnage 22 |
| Iris | Ketch | Built: 1891 Tonnage 12 |
| Iris | Cutter | Built: 1860 Tonnage 17 |
| Irish Lily | Cutter | Built: 1899 Tonnage 4 |
| Iris Moana | Fairmile | Built: 1943 Tonnage 67 |
| Irish Maple | Built: 1924 Tonnage: 19 | |
| Irishman | Built **** Tonnage ** | |
| Iron Age | Paddle Steamer Ferry | Built **** Tonnage ** |
| Iron Age | Towboat | Built **** Tonnage ** |
| Isabel | Cutter | Built **** Tonnage 12 |
| Isabella | Brigantine | Built **** Tonnage 82 |
| Isabella | Schooner | Built: 1845 Tonnage 17 |
| Isabella | Schooner | Built: 1851 Tonnage ** |
| Isabella | Schooner | Built: 1859 Tonnage 21 |
| Isabella | Ketch | Built: 1866 Tonnage 51 |
| Isabella Anderson | Schooner | Built: 1874 Tonnage 85 |
| Isabella Jackson | Schooner | Built: 1860 Tonnage 42 |
| Isabella Pratt | Schooner | Built: 1875 Tonnage 71 |
| Isabella Ridley | Barque | Built 1858 Tonnage 233 |
| Isabelle | Schooner | Built **** Tonnage 129 |
| Island Lily | Brigantine | Built: 1877 Tonnage 122 |
| Isle of Bueaty | Schooner | Built: 1870 Tonnage 6 |
| Isobel | Cargo ship | Built: 1957 Tonnage: 6,218 |
| Isobel Du Fresne | Ketch | Built: 1891 Tonnage 12 |
| Ivy | Built **** Tonnage ** | |
| Ivanhoe | Schooner | Built: 1864 Tonnage 71 |
| Ivanhoe | Schooner | Built: 1891 Tonnage 152 |