We travelled this itinerary in March. One of our sons was recovering from orthopedic surgery and was limited in what he could do, and had his power chair, which limited our shore options.
In St. Thomas, do as the CMs do...the Guest Services CMs shared their plans - when they have time off, many of them disembark, and make their way to the local Chinese restaurant (straight across the buys road). The food was good, and if you spend $10, you get a wifi code. There was a group of them at a corner table - looked a little weird, all of them sitting together, all of them on their devices!
After months in hospital...free wifi and good food, with a little sun on the side, was just what our teenaged son wanted!
In St. Maartin, we took the water taxi, and eventually chose one of the restaurant/bars, again for the free wifi. We ordered ice cream and drinks, no stated minimum, but we probably had ordered plenty after my husband and other son arrived. It worked out well, we surfed the net, they had fun in the surf!