Boat schedules?

The official boat schedule site that is kept up to date by the Visitor Center staff is harborlookout.com  -- duluthboats.com is still around and has lots of good information and history including longer-range and special boat schedules. 
So keep both bookmarked for your reference.

Note also that this is a "work in progress" with lots of kinks to work out.  timing should get better as time goes on.
Also, I am not the one who operates and manages it, so, I look forward to refinement just like you.