I was at Charlevoix earlier this month. The lake was rough and waves were coming up the river. Sailboats were waiting in the lake outside the river entrance rather than hover between the breakwalls. I noted the bridge opens precisely on schedule. I expect the bridge would open on demand for vessels seeking shelter from severe weather. BTW, I have the bridge listed as 16 ft. Alan Lloyd Author, Great Loop Navigation Notes _www.NavigationNotes.com_ (http://www.navigationnotes.com/) Visit web site for more information. In a message dated 9/22/2011 10:04:49 A.M. Eastern Daylight Time, cyggie002@aol.com writes: Charlevoix has a bridge which opens on the half hour and hour. When closed the bridge has an overhead clearance of approximately 17'.