St Thomas Spotlight 5 Star Island Tour

[CWolsten]

We have booked this excursion at 1pm. Description says it is 3 1/2 hrs. My husband is always concerned about getting back to the ship in plenty of time. The excursion ends " the tour leads directly to main street for bountiful recommended shopping, you can return to the ship at your leisure by harbor cruise "
The ship leaves at 6pm. Do we have enough time if we head immediately back to the ship? We do not care about shopping.