This is copied from an article about the WL. I think the boat ride itself is less than 10 minutes and the boats run every 20 minutes or so.
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 during the day. Always check with the boat Capitan as to which resort the boat will be headed for next, in the am they travel clockwise WL, CR, Ft Wilderness at 3:00pm they reverse the route to counter clockwise WL, Ft. Wilderness, CR. The operating hours are 6:45am-11:30pm (Times & Schedulles are subject to change)