I would not worry about the computer unless you want to take it. The current at St. T was very light when we dove there. The dive operation was Underwater Adventures. I am not sure if they have a website but you might check. If you have never done a dive as an excursion from a cruise ship they are usually very safe shallow dives as they get divers from all experience levels. I generally just bring my regulator when cruising and diving as it does not take up a lot of space.