Everyone boarded through the side at Skagway and unloaded through the same side at Haines. We were one of the last to load and drove up the ramp, turned left and parked in the middle lane facing aft. When we unloaded, we were directed to loop around the central bulkhead and drive toward the bow, make a right, and headed out the door. We had no problem getting on or off, made the turns with no trouble, and, as others have said, everything was handled very professionally.
Our experience was exactly as stated in the above quote. We took the Walaspina ferry from Skagway to Haines in June of this year. Our truck and fifth wheel were measured at the dock to be 46 feet. We were the longest rig and we were the last ones on the ferry. We figured the total cost was about the same as we would have spent in diesel if we had driven from Skagway to Haines. The ferry trip was a great experience and I wouldn't hesitate to do it again. We met several people who drove to Skagway and skipped Haines because they were told it would be too expensive. It's not.
So don't be afraid to try it! It was really fun and Haines turned out to be one of our favorite places.
Here's a link to my blog post about taking the ferry
Taking the Alaskan Ferry to Haines