When you board and if your cabin is all ready, you can go and drop off your carry-on stuff and explore the rest of the ship. Have heard that sometimes, you are able to board and may have a small wait til you can go to your cabin, hopefully yours will be all set .
We boarded the ship at 12:45 p.m. (sail time 5:00 p.m.), and went straight to our cabin. We unpacked, got familiar with the room, then headed out to lunch and a tour of the ship. Have a wonderful time!