In January we went to the Baths through
DCL. The excursion was from around 9am to around 3pm. Included lunch.
They picked us up at the ship. while everyone else left through the gangways to the pier, we exited the other side of the ship -- right onto the ferry / tender that took us to virgin gorda. Then a taxi ride to the baths. Then we were pretty much on our own - until 1pm when we were expected back up at the entrance for lunch and "shopping".
We went down to the Baths.... we looked at the little beach and decided to go to Devils Bay. To get there you go through the "caves".
Remember the Baths are made up of Giant boulders that are sitting on the ground and on top of each other. The "caves" are the gaps / cracks between the rocks. To make this trek you have to climb some rocks (there's a rope to help you), climb up/down some ladder like stairs, crawl through some gaps. Was actually a lot of fun. We got lost several times (wrong forks in the "road" - but lots of laughs). Finally a park guide showed up and said that if the water was over knee deep we were going the wrong way and that we needed to follow the arrows (yea right). The arrows were painted "a hundred years ago" and very faint, you knew that you were going the right way when you stumbled upon one

)
We brought too much stuff - we had some bags with our towels, masks & snorkels and a dry clothes to change into on the way back ... well we used the towels .... Your kids would have no problem going through the caves .... they would probably leave you in the dust if you let them. I'm 6-2 and 250 lbs. I made it no problem. Had to crawl on hands and knees at one point. Oh yea, skip the flip flops, wear water shoes / athletic sandals. We took our time going through the caves and had about an hour in the water at Devils Bay.
And when our time was up at the beach. We just walked up the path to the "car park" and were at the facilities at the entrance to the Baths. Was an easy walk and less than 15 minutes.
Lunch and drink (water/coke products) were provided. Adult beverages available for purchase. Lunch was pretty good: Salad, Mac and Cheese, BBQ Chicken and Ribs, and some fish. I don't remember if there was something for dessert. Oh yea, they had Fried Plantains - those count as dessert
We had time to shop - but we don't. We actually found a few post cards. Then it was back onto the taxis to the harbor, back onto the ferry to Tortola. This time they dropped us of on the pier near land - to entice us to go shopping some more, but we chose to return to the ship.
Even with the rain when we first arrived at the Baths, it was a very fun day.