| McDowell, Robert; ISMA Directory; 1896 | ISMA Directory | 1896-00-00 | | Captain |
| McDowell, Robert; ISMA Directory; 1898 | ISMA Directory | 1898-00-00 | | Captain |
| McDowell, Robert; ISMA Directory; 1899 | ISMA Directory | 1899-00-00 | | Captain |
| McDowell, Robert; ISMA Directory; 1900 | ISMA Directory | 1900-00-00 | | Captain |
| McDowell, Robert; ISMA Directory; 1901 | ISMA Directory | 1901-00-00 | | Captain |
| McDowell, Robert; ISMA Directory; 1902 | ISMA Directory | 1902-00-00 | | Captain |
| McDowell, Robert; ISMA Directory; 1903 | ISMA Directory | 1903-00-00 | | Captain |
| McDowell, Robert; ISMA Directory; 1904 | ISMA Directory | 1904-00-00 | | Captain |
| McDowell, Robert; ISMA Directory; 1905 | ISMA Directory | 1905-00-00 | | Captain |
| McDowell, Robert; ISMA Directory; 1906 | ISMA Directory | 1906-00-00 | | Captain |
| McDowell, Robert; ISMA Directory; 1907 | ISMA Directory | 1907-00-00 | SOCAPA | Captain |
| McDowell, Robert; ISMA Directory; 1908 | ISMA Directory | 1908-00-00 | | Captain |
| McDowell, Robert; ISMA Directory; 1909 | ISMA Directory | 1909-00-00 | THOMPSON, ALEXIS W. | Captain |
| McDowell, Robert; ISMA Directory; 1910 | ISMA Directory | 1910-00-00 | THOMPSON, A. W. | Captain |
| McDowell, Robert; ISMA Directory; 1911 | ISMA Directory | 1911-00-00 | | Captain |
| McDowell, Robert; ISMA Directory; 1912 | ISMA Directory | 1912-00-00 | | Captain |
| McDowell, Robert; ISMA Directory; 1913 | ISMA Directory | 1913-00-00 | | Captain |