Duluth, Minnesota four Catholic schools with coverage up to grades 6 or 8, two Protestant schools, two Montessori schools, and six other charter and private schools. Due to its proximity to the Great Lakes, Duluth is the location for the Large Lakes Observatory. The Large Lakes Observatory operates the largest university-owned research vessel in the Great Lakes, the R/V Blue Heron. Built in 1985 for fishing on the Grand Banks, the Blue Heron was purchased by the University of Minnesota in 1997, sailed from Portland, Maine, up the St. Lawrence Seaway to Duluth, and converted into a limnological research vessel during the
Duluth Ship Canal of adverse weather. Around a thousand vessels a year ship from the Duluth–Superior port. The construction of the first locks on the St. Marys River in 1855 allowed for navigation between the lakes, and Superior Bay presented itself as an attractive harbor. From the point of view of Duluth residents, however, arrangements were less than satisfactory, as ships from that city had to pass Superior, Wisconsin on the way to the lake, as the only natural outlet was between Minnesota Point and Wisconsin Point at the far end of the bay. Also, while sheltered, the bay was not naturally as