We had the best day on Jost Boat seeing the Bath's and hiking in the British Virgin Islands/ Virgin gorda, snorkeling at Norman island (great fish and jellyfish as well as corals to see and the island which inspired the book "treasure island.")
The crew of three (I only remember one name, Dan), was friendly and helpful throughout the day. If you are on the fence about this excursion, I felt it was well worth it and the most fun day we had on our trip. Book it! The crew and excursion was very kid friendly.
Tips: bring or wear a swimsuit with fast-drying layers. When you hike through the baths it isn't more than knee-deep. Bring a water bottle to take on the hike (they do have them available for purchase on site and do take credit card).
We saw plenty of elderly and infirm individuals not in our party attempting to make the trek with varying degrees of success. It is 1.5 miles round trip for the hike with lots of steep and slippery ascents and descents as well as narrow passages through and underneath rock formations where short and slender individuals will have an advantage. I agree with another user's tip that if your party is athletic/agile, try to politely get toward the front of the line hiking back out of the baths as there are many slippery, narrow paths and the less fit members of the group took extra time getting through which created a bottleneck effect. Everyone made it in time for lunch at the restaurant and the food was delicious, in particular the pulled pork. They did accommodate for food allergies without issue.
The hike and snorkel were great for kids, my 5 and 7 year olds snorkeled for the first time and there was plenty of kid size equipment including life vests on board. Our 3 year old had to be carried for parts of the baths hike to keep up with the group so plan accordingly if you have a baby or toddler. The painkiller drinks on the way back were delicious. Customs process was pretty painless and efficient coming back into the USVIs.
Another tip: the complimentary breakfast did not include any coffee so if you like to caffeinate in the AM make sure you do so prior to boarding or bring along with you.
Another tip: in addition to sunscreen, bring bug spray, the brief wait while loading the group open air taxi from the dock at the British Virgin Islands to the hiking site had some mosquitoes.