I would suggest that you arrive early for your ADR @ WCC and notify them when you check-in (also let your server know) that you have the cruise scheduled for later that night. You will need to catch one of the Blue Flag Resort Boats. To arrive at the CR in time you should probably be at the boat dock at Wilderness Lodge at the latest 7:20pm.
The Blue Flag Resort Boats Run continuously between the three resorts (Wilderness Lodge, Contemporary Resort and Ft. Wilderness Campground) there are at lest two of these smaller boats that run two routes one clockwise around Bay Lake the other counterclockwise. Always check with the boat Captian as to which resort the boat will be headed for next, this will save you some time by not riding to say Ft. Wilderness if you want the Contemporary.
The smaller Blue Flag Resort Boat holds appx 30 guest are open to the elements and require a guest to transfer from wheelchairs to the boat with a step down. (strollers also need to be folded)
Blue Flag Resort Boats hours of operation are 7:00am till 10:00pm