When you disembark you go across the street to the parking lot. There is a white canopy to your left where the rental shuttles pick you up. We had a Budget reservation, ans it was a short ride to the agency. We were lucky as the shuttle (van) was waiting and he took us and another family right away, so I can't comment on the waiting time if there was a crowd.
I think you drop off the car at the agency and they will bring you to the dock.