First: - "The Baths" are NOT on Tortola - they are on Virgin Gorda. Cruiseships stop at Tortola and from there it is possible to take a ferry or an excursion that goes to Virgin Gorda.
What are they ? A little hard to describe - you might want to do a web search to find some photos. They are basically a huge jumble of giant (car-sized and bigger) boulders on a beach (and into the ocean). There is a passage through (and over and around) the jumble. It is quite an experience to go through the Baths (some climbing and some squeezing is involved but it is very doable unless one has serious mobility problems. I have done it and I have bad arthitis). At the other end is a nice beach with great snorkeling. Quite frankly inmy opinion it is one of the best excursions you can take if your ship stops in Tortola.
We went to the Baths on our own - very easy to do. It is a short walk over to the ferry in Tortola. 2 different companies (Speedy's and Smith's) will fight for your business - go with the best deal - about $20-$25 RT including taxi to the Baths but be sure to ask that the taxi is included. The ferry takes about half an hour there and back if I remember right. There are several ferry times for both companies so you may want to check the one that fits your ship schedule the best. There is a small fee at the Baths too. After a few hours exploring at the Baths there is a nice restaurant and pool at the top that is reasonably priced. Beautiful view too.
It was one of our favorite 'adventures'.
The baths are pretty much what is described above. A nice beach at the bottom of a path that meanders down a hillside . The beach is marked with giant boulders in and around the water. There is also a pathway in , under and around the boulders that will take you to the adjacent Devils Beach. This one is not for someone with back or knee problems.
On Legend, your stay in Tortola is only until 2pm, all aboard is at 1:30 pm. Ferries in the BVI are notorious for NOT being on schedule. I would (and have) gone to the Baths as a ship's excursion rather than independently. It will be a few dollars more, but will be a lot cheaper than a last minute flight back to NY.
Any other time I have taken a ferry in the BVI's it has been anywhere from 30 minutes to an hour late in arrival.
For information about Tortola and Virgin Gorda (and anything else about the BVI's ) check out BVIwelcome.com
I visited the Baths and I have knee problems BUT I don't use a cane. As long as you take the downhill path slowly and carefully that should not be a problem (my husband assisted me in one or two tricky spots) You should be able to at least get a little way into the Baths. At the first "big' obstacle you can judge if you should go further - if you can make it through that area, the rest will be OK. The main problem for people with bad knees is the need to crouch down occasionally. Luckily for me - I am VERY short (5 feet) so crouching was not a problem and in one spot where some people crawled (just for a foot or two) I sat down and inched by on my bum. I think a very tall person with bad knees might have more difficulties.
Anyone can access the Baths who can walk, it may take some time and terrain can have a rock to step up to or around , but , there is no climbing, stooping or scrambling involved. . The trail the person above is describing is one that runs between the Beach at the Baths and the Beach at Devil's Bay. You do not have to take that trail to access the Baths.
To clarify: - actually the trail I was describing is the trail that goes THROUGH the Baths This trail goes from the beach at the entry to the Baths to Devil's Bay. To me this trail is part of the point of going to see The Baths. Otherwise one only sees the exterior of the Baths - interesting in its own right but not as fascinating as actually entering the Baths. Going through the Baths does indeed require crouching and climbing. The trail downhill from Top of the Baths to the entrance to the Baths MIGHT be a little challenging for someone with a cane but is doable by anyone who can walk downhill on uneven ground. I have arthritis in my knees and required some minor assistance at one point from my husband when going downhill to the Baths and much more assistance when I went THROUGH the Baths but I am so glad I made the effort.