I also have MS and use a rollator for short distances and a folding manual wheelchair for longer walks. We did this cruise on Royal Caribbean Anthem of the seas. We had a tender port in Bar Harbor. We used a ferry type of boat that I rolled onto. Once on shore, there was a series of ramps to traverse, some steep. But we made it! Since I was able to climb a few steps we were able do excursions that included a coach ride.
Paula