Cruise lines vary in accommodations for people with disabilities

While most cruise lines feature two dozen or more wheelchair-accessible staterooms, public areas can provide a challenge, with too-narrow passages, inaccessible bathrooms and inconvenient barriers, according to this article. Newer ships are changing, however, and potential passengers are advised to check with a line's special-services desk or a knowledgeable travel agent before booking. MSNBC/Tripso

Crew members are available on almost every ship to assist disabled passengers
with buffet service and with embarkation and disembarkation.
Here are some
things to consider before booking your cruise:

1. 
   There are no additional fees for handicapped-accessible staterooms but, like all cabins, they are offered at different price points depending on size, location and amenities. There are a limited number of these accommodations on board each ship, so book early to avoid disappointment.
2. 
   When booking a cruise, ask to see the ship's deck plans or view them online. That way you can see where the handicapped-accessible staterooms are and can reserve the one that works best for your individual interests and needs; you might, for example, wish to be near the elevators, lounge or weight room.
3. 
   Contact a knowledgeable travel agent or call the cruise line's special services desk to better understand all the ship's requirements and limitations. For example, some lines require travelers with disabilities to be accompanied by an able-bodied companion. Make sure all public rooms are accessible, and make sure the ship offers a good number of elevator banks.
4. 
   Find out the accessibility of ports of call, and try to choose an itinerary that does not include tenders, small boats used to bring passengers to shore from the ship's anchor point. These boats are usually not equipped to handle wheelchairs.
5. 
   Review shore excursions carefully since many are not appropriate for travelers with limited mobility. Read the brochure descriptions and avoid those excursions identified as requiring heavy exertion. Most cruise lines identify wheelchair-accessible tours in their brochures.
6. 
   Let the cruise line know you are using a wheelchair so staff can make an appropriate table assignment in the dining room. You'll want to have easy access to bathrooms and elevators. Be sure to request a wheelchair, or assistance with your own wheelchair, if you will need one for embarkation and disembarkation. There may be a short wait for the chair, but you will receive priority boarding.
7. 
   Check with the cruise line if you are interested in bringing an electric scooter or renting one in port; policies vary.