The first thing you need to do, if you haven't yet, is to let RCCL know about the wheelchair. Visit their website for a special number to call.
If you have need of it for long walking trips, be prepared to use it quite a bit aboard ship. Those corridors and passgeways can be very long, and can pitch and roll in ways that might be visually un-noticeble. But you will feel such motion in your sense of balance, and in the tensioning of leg and back muscles, particualrly at the hip, knees, and ankles, if you are standing. You will certainly not regret being in the wheelchair, if only to get from place to place aboard ship.
The best way to get it aboard is to be seated in it as you embark and disembark. Terminal check-in lines can be long and waiting times challenging even to athletes. In fact, the folks at the terminal will probably appreciate it, and see it as you looking out for your own safety and comfort. And--shhhhh, don't tell anybody--it will get you aboard a little sooner than some of the folks standing in line.
I may dwell on the land, but I live at sea!
Sensation 2/03 I disembarked, but never really left the ship.
Enchantment 9/03 Just had to go back.
Inspiration 3/04 Just have to go back again, and again, and again...
Sensation 04/05 The vessel made me do it!