 Undated USCG photo | |
 | |
| Location | Saginaw Bay, Michigan |
|---|---|
| Coordinates | 44°1′6″N 83°32′14″W / 44.01833°N 83.53722°W |
| Tower | |
| Constructed | 1939 |
| Foundation | 50-foot (15 m) diameter concrete pier[5] |
| Construction | Steel-sided tower |
| Height | 65 feet (20 m)[1] |
| Shape | Art Deco |
| Markings | white, gray scaffold atop |
| Fog signal | Every 30 seconds, operates year round.[6] Radio beacon signal transmitted at 296 kHz, and emitted a group of 0.5 -second dashes for 15.5 seconds, followed by 14.5 seconds of silence.[3] |
| Racon | oui  |
| Light | |
| First lit | 1939 |
| Focal height | 75 feet (23 m)[2] |
| Lens | 14.8-inch (375 mm) lens[6] |
| Intensity | 15,000 candela[3] |
| Range | 9.6 nautical miles; 18 kilometres (11 mi) |
| Characteristic | red flash every 6 seconds[4] |
Gravelly Shoals Light is an automated lighthouse that is an active aid to navigation on the shallow shoals extending southeast from Point Lookout[7] on the western side of Saginaw Bay. The light is situated about 2.7 miles (4.3 km) offshore and was built to help guide boats through the deeper water between the southeast end of Gravelly Shoals and Charity Island. Architecturally this is considered to be Art Deco style.[8]
- ^ Pepper, Terry. "Database of Tower Heights". Seeing the Light. terrypepper.com. Archived from the original on 2000-09-18.
- ^ Pepper, Terry. "Database of Focal Heights". Seeing the Light. terrypepper.com. Archived from the original on 2008-08-30.
- ^ a b "Seeing The Light - Gravelly Shoal Lighthouse". www.terrypepper.com.
- ^ Light List, Volume VII, Great Lakes (PDF). Light List. United States Coast Guard.
- ^ Detroit News , Interactive map on Michigan lighthouses.
- ^ a b Rowlett, Russ. "Lighthouses of the United States: Michigan's Eastern Lower Peninsula". The Lighthouse Directory. University of North Carolina at Chapel Hill.
- ^ Wobser, Dave, Gravelly Shoal Light Archived March 3, 2016, at the Wayback Machine, at boatnerd.com.
- ^ "Lighthouse Digest - America's Lighthouse News & History Magazine". www.lighthousedepot.com. Archived from the original on December 29, 2004.