Book a day trip on the "bad kitty". It is the best. We were there in january/february.. they went to Virgin Gorda to get passports approved, the baths with a guided tour thru the boulders,, cooper island for lunch which is great.. on the beach,
snorkeling at the caves on Norman Island, and white bay Yost Van Dyke,a beautiful beach and home to soggy dollar .. Great trip and great crew. worth every penny..I would do it again in a minute.. it is still pricy for ferry.. so why not give this a try. !

Yes, it is possible to take a ferry. One of the day boats (see thread on BVI trips) is probably more convenient and user friendly. Open bar, lunch stop and snorkeling vs sitting on a hard ferry bench with diesel fumes...hmmm...

BTW, it's Jost Van Dyke. 😉

YES,
If you want to visit the Baths you can either book w an organized trip such as some others have already listed. But I find taking the public ferry from St John directly to Virgin Gorda much better. If you go with an organized group you will go to the baths and spend about 2 hours there and them some other nice stops. But, if you take the public ferry there you will be able to spend the entire day there. There is so much to see at the Baths. You can spend the entire day going up and over and around boulders and you just keep coming to another beach that is more beautiful than the next. t truly takes hours to explore. If you take the public ferry from St John you will need to use the "Interisland" ferry services. They only go about 2 days a week so you will need to find out.. Make a plan. You get at ticket in Cruz Bay, not at the regular ferry dock but just around the corner where you will see other ferries backed up to shore. You will buy a ticket at the "office" (a hut) and board right there. Check on the passport issue and expect a charge to go thru customs, it might still be $15. The ferry takes you to Virgin Gorda and u will go thru customs there. Then take a taxi to the ParK. These guys are awesome, get his name and tell him you are on the boat and he will absolutely be there to pick you up to get you back in time. There is a nice bar and grill and few stores at the drop off point so be sure to leave enough time for a burger before you leave. He will take you back to the boat and you will go thru customs in St J on return. I promise you will love it!

Sumerwaters... How long does it take to go from Cruz Bay to Virgin Gorda on the Interisland ferry?

mmmm, I think about an hour and 15 minutes.
check out the ferry schedule on this page under quick links, be sure you know which days the ferry runs.
Ticket go on sale about 30-40 before departure, It is a painstaking slow line as identification is checked here.
Seems like it was about $60 bucks. We usually take a small carry on cooler with a few beverages and pbj's.
It's a very nice scenic boat ride along coastlines. Nice views. Bring a video camera if you have one.

Is there a path around the boulders or do you have to do a lot of climbing and swimming. If you've read my other posts, you'll know that I do not swim. How difficult is it to explore the boulders?

Straycat,
You do not have to swim through the boulders, it's so beautiful, it's mainly wading until you get to the area for snorkeling and it has a beach right there. The boulder's are awesome spots for pictures, especially if you can hit the sunlight coming through at the right times. It has been a few years since my trip to the Baths but I do not believe swimming would be anything to keep you away.