I've seen that before I believe. It appears that when they're not sure of how much room they have to turn normally they take the safe way out. I've never seen it done in daylight.
I have seen other, albeit shorter vessel's, performed this maneuver in Two Harbors. This is the first time I saw a footer do it. Actually it is a reciprocal of their docking courses, this is the way most vessels arrive and dock in Two Harbors? According to Boatnerd she has a pair of CP props, a stern, and a bow thruster. That, and there are some awesome ship handlers on the Great Lakes. Greg Hayden Vista CA
A page out of Algoma's book, They used to back out all the time. 3rd trip in a row for Capt Terry's boat