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.

[11][12] When built according to its original specifications, the contractor warned that the foundation was inadequate to withstand the buildup of ice, and put in a bid for a contract modification.

It is supplemented by a standby 110 candela 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).

[3] The National Data Buoy Center lists the Site Elevation as 588 feet (179.2 m) above sea level; an automatic readout for wind, waves and weather is operated there.

[15][16][17] A good passing view of the light can be had while riding the ferry from Au Gres to Charity Island, which is 10 miles (16 km) to the east in the middle of Saginaw Bay.