Another option to River Cruising in Europe is a fully accessible bus tour with a wheelchair lift. We booked one last year with Limitless Travel and they are surprisingly affordable. The owner of the company, which is based in Birmingham, UK has Muscular Dystrophy.
I started a group for women who want to travel but may need special accommodations or extra planning for whatever reason. Some may just require a slower pace and more frequent opportunities to rest. Others may use mobility devices or have medical conditions to be managed. Some may be perfectly healthy but are caregivers for loved ones who need special accommodations. My hope is that this group can grow into a valuable resource by offering tips, reviews and support. If there is enough interest, I may try to plan some group trips for those who are single and may be intimidated by the prospect of traveling alone. These trips will be a slow pace and always thoughtful and respectful of each members individual limitations. Please feel free to join if you think this group would be a good fit for you.
They do have accessible bus tours in the Caribbean. I have found them by Google for the fb groups i run for my cruise groups. Just type in accessible bus tours for whatever island you want and a list will come up. Cruise lines usually have a tour or two that is accessible if you are cruising in each port.