Gravelly Shoal Light

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Gravelly Shoal Light
Source:U.S. Coast Guard archives

Gravelly Shoals Light is an automated lighthouse on the shallow shoals extending southeast from Point Lookout on the western side of Saginaw Bay. The light is situated about 2.7 miles offshore at 44°01′06″N, 83°32′14″ 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.^[1]

The light tower was built in 1939 and replaced an earlier gas-lit buoy. It also displaced the Charity Island Light, which was constructed in 1857, and operated until 1930.

This light is designed as an autonomous automated electrified station. It is under the control and maintenance of Coast Guard Station in Tawas City, Michigan. Ordinarily it displays a 15,000 candlepower 375 mm light powered by a 120 volt electric lamp. Power is supplied through a submarine cable, which crosses the shoal from Point Lookout. The 75-foot focal plane makes its flash (1-second every 5 seconds) visible for 16 miles. It is supplemented by a standby 110 candlepower acetylene light with a half second flash every three seconds -- which activates automatically if there is a power failure. In foggy weather, mariners are warned by twin compressed-air two-tone #3 diaphones, which operate on a 30-second cycle (3-second blast followed by 27 seconds of silence).^[2]

The Nation Data Buoy Center lists the Site Elevation as 179.2 meters above sea level.

The National Weather Service operates an automated weather observing station at the lighthouse.

An added large steel tower atop the light is a radio beacon. The 1953 Coast Guard Light List indicates that the signal transmitted at 296 kilocycles, send forth a group of 1/2-second dashes for 15.5 seconds, followed by 14 1/2 seconds of silence. As of 2001, both the light and radio beacon served as active navigational aids.^[3]

A good passing view of the light can be had while riding the ferry from Au Gres to Charity Island, which is ten miles to the east in the middle of Saginaw Bay.^[4] Tours of the Charity Island (and even dinner cruises) are available, which can include the privately-owned, rebuilt Charity Island Lightlightkeeper's house]]. They are available from Charity Island Transport, Inc. in Au Gres, Michigan on the mainland, south of Tawas.^[5]

1 See also
2 Notes
3 Bibliography and further reading
4 External links

[edit] See also

Lighthouses in the United States

[edit] Notes

[edit] Bibliography and further reading

Bibliography on Michigan lighthouses.
Hyde, Charles K., and Ann and John Mahan. The Northern Lights: Lighthouses of the Upper Great Lakes. Detroit: Wayne State University Press, 1995. ISBN 0814325548 ISBN 9780814325544.
Oleszewski, Wes, Great Lakes Lighthouses, American and Canadian: A Comprehensive Directory/Guide to Great Lakes Lighthouses, (Gwinn, Michigan: Avery Color Studios, Inc., 1998) ISBN 0-932212-98-0.
Penrod, John, Lighthouses of Michigan, (Berrien Center, Michigan: Penrod/Hiawatha, 1998) ISBN 9780942618785 ISBN 9781893624238.
Penrose, Laurie and Bill, A Traveler’s Guide to 116 Michigan Lighthouses (Petoskey, Michigan: Friede Publications, 1999). ISBN 0923756035 ISBN 9780923756031
Pepper, Terry. Seeing the Light: Lighthouses on the western Great Lakes.
Putnam, George R., Lighthouses and Lightships of the United States, (Boston: Houghton Mifflin Co., 1933).
Wagner, John L.. Beacons Shining in the Night: The Lighthouses of Michigan. Clarke Historical Library, Central Michigan University.
Wagner, John L., Michigan Lighthouses: An Aerial Photographic Perspective, (East Lansing, Michigan: John L. Wagner, 1998) ISBN 1880311011 ISBN 9781880311011.
Wright, Larry and Wright, Patricia, Great Lakes Lighthouses Encyclopedia Hardback (Erin: Boston Mills Press, 2006) ISBN 1550463993.