Harbor

• Grassy Island lakeward to entrance light: 11.5 miles
  Maintained at 26' below low water datum.
  Channel width is 500'.
  
• Grassy Island to the Mason Street Bridge (Mile 2.25)
  Maintained to 24' below low water datum.
  Channel width is 300'.
  
• Mason Street Bridge (Mile 2.25) to Georgia-Pacific turning basin
  Maintained to 22' below low water datum.
  Channel width is 300'.
  
• Navigation channel from Georgia-Pacific to De Pere Dam is no longer maintained.
  
• Low water datum is 577.5' above mean level at Rimouski, Quebec, Canada.