For those with drafts of less than five feet, the Blynman Canal offers the opportunity to travel from Gloucester, MA to Ipswich Bay without making the long journey around Thatcher Point, Rockport and Halibut Point.
The beginning (Gloucester side) of the Blynman Canal is dotted with two large marinas, which offer transient space at their well protected docks. The Blynman Canal Marinas are often preferred for the protected nature of the canal.
Use NOAA Chart 13279.
The Blynman Canal has a controlling depth of 5.8 feet at its shallowest (from the railroad bascule bridge north to the Annisquam River) and two opening bridges to negotiate at its southern end. The canal allows passage from Western Harbor near Gloucester to the opening of the Annisquam River at the town of Annisquam on Ipswich Bay.
When approaching from the south through Gloucester Harbor, pay close attention to red nun "6" marking the series of ledges that push southwestward from Tenpound Island. Once you have cleared red nun "6," proceed north toward and white can "BC," which marks the entrance to the Blynman Canal.
The canal's southern end is crossed with a bascule bridge and railroad bascule bridge, respectively, as you move north. The first bridge has a closed vertical clearance of eight feet with 38 feet of horizontal clearance in the center span, and the railroad span has a closed vertical clearance of 16 feet with 38 feet of horizontal clearance in the center span. The bridges can be hailed on VHF Channel 13.
Local Notices to Mariners are available online from the U.S. Coast Guard.