It really depends upon the ship. Some are loaded on the side, others on the end or front. Some are large enough that when you drive down into the ship, you just get in a line inside. Others you have to back the rv into the line. I saw one guy that had to back his 35' 5ver down the ramp and into the ship.
We did it both ways. When you have to back into the line (once you are in the bowels of the ship) there will be people who will guide you expertly. One of the ships was so large that I actually drove the mh down one side of the ship (while inside), turned a 180 at the end of the ship and then drove up the other side and parked.
Don't worry, they will take real good care of you and your rv. And as far as "measuring", nobody ever checked mine. When I made my reservation, I didn't check the over 102" box.
Ron