Machias Seal Island (Maine)
Historical Light List Characteristics
| 1940 | Fl W 3s. W14. | USCG Light List (Atlantic): 10 |
| 1943 | USCG Light List (Atlantic): 14 | |
| 1945-1947 | ||
| 1950-1952 | ||
| 1953-1955 | USCG Light List - Vol. I-VI: 94 | |
| 1957 | ||
| 1959-1960 | USCG Light List - Vol. I-V: 95 | |
| 1961 | USCG Light List - Vol. I: 95 | |
| 1963-1965 | ||
| 1966 | USCG Light List - Vol. I: 204 | |
| 1969-1970 | ||
| 1971-1972 | Fl W 3s. | |
| 1973-1975 | Fl W 3s. W14. | |
| 1976-1979 | Fl W 3s. W17. | |
| 1982 | ||
| 1987 | USCG Light List - Vol. I: 1270 | |
| 1990-1992 | USCG Light List - Vol. I: 1065 | |
| 1993-1996 | USCG Light List - Vol. I: 1090 | |
| 2004 |
Historical Light List Optics and Structures
| 1940 | N/A | N/A | 82 | White octagonal concrete tower. | USCG Light List (Atlantic): 10 |
| 1943 | USCG Light List (Atlantic): 14 | ||||
| 1945-1947 | |||||
| 1950-1952 | |||||
| 1953-1955 | White octagonal tower. | USCG Light List - Vol. I-VI: 94 | |||
| 1957 | |||||
| 1959-1960 | 60 | White octagonal tower with red roof. | USCG Light List - Vol. I-V: 95 | ||
| 1961 | USCG Light List - Vol. I: 95 | ||||
| 1963-1965 | |||||
| 1966 | USCG Light List - Vol. I: 204 | ||||
| 1969-1974 | |||||
| 1975 | White octagonal tower. | ||||
| 1976-1979 | White octagonal tower, red top. | ||||
| 1982 | |||||
| 1987 | USCG Light List - Vol. I: 1270 | ||||
| 1990-1992 | USCG Light List - Vol. I: 1065 | ||||
| 1993-1996 | USCG Light List - Vol. I: 1090 | ||||
| 2004 |
Historical Light List Audible Fog Signals
| 1940 | DIAPHONE, air: group of 2 blasts every 60 sec. | None | USCG Light List (Atlantic): 10 |
| 1943 | USCG Light List (Atlantic): 14 | ||
| 1945-1947 | |||
| 1950-1951 | |||
| 1952 | DIAPHONE, air; group of 2 blasts every 60 sec. | ||
| 1953-1955 | DIAPHONE: gp of 2 blasts ev 60s. | USCG Light List - Vol. I-VI: 94 | |
| 1957 | |||
| 1959-1960 | USCG Light List - Vol. I-V: 95 | ||
| 1961 | USCG Light List - Vol. I: 95 | ||
| 1963-1965 | |||
| 1966 | USCG Light List - Vol. I: 204 | ||
| 1969-1973 | HORN: 2 blasts ev 60s. | ||
| 1974-1975 | HORN, 2 blasts ev 60s (3sbl). | ||
| 1976-1979 | HORN: 2 blasts ev 60s (3sbl). | ||
| 1982 | HORN: 2 blasts ev 60s (3s bl). | ||
| 1987 | HORN: 2 blasts ev 60s (3s bl). | USCG Light List - Vol. I: 1270 | |
| 1990-1992 | USCG Light List - Vol. I: 1065 | ||
| 1993-1996 | USCG Light List - Vol. I: 1090 | ||
| 2004 | HORN: 2 blasts ev 60s (3s bl). |
 |
1832 - Present (Exact location of current 1915 lighthouse. Location of original 1832 towers are assumed to be close.) |