Loading depends on access to the ramp. Sometimes from the side, sometimes from the end. Also depends on where you are getting off. We got on and off 5x with our Class C. They put Busses, trailers, trucks, bikes you name it.
Call the 800 number and they will help you out. We made all our reservations over the phone since we had trouble understanding the web site info. (no info on arrival times and we wanted to lay over at each stop). We were on 4 different ships for our trip.
Also consider the cost, you pay by the foot, length, height and width.
For a fiver, that may not include while connected to the truck. You will not have access to the truck or trailer except in port, and they will secure your propane in the off position while on board.
We were able to boondock the night before in the ferry boarding area a couple of times. Departure times depend on the tides and we usually had to be there 2 hours before and most were between 3 and 6 in the morning.
Great trip, good reasonably priced food. Crews were topnotch loading and unloading us. You drive your own vehicle on and off with them guiding you from the lot till it is parked.