Recommendations for 1st Timer?

Will be arriving on the Epic, March 22nd. Looks like we'll be one of 4 ships between the 2 docks that day (approx 15,000 pp). Ship is only there from 7am until 2pm, not much time. We're a party of 5 couples - 3 of which have been on St. Thomas, and 2 of us never. We've all agreed to enjoy the day together. I'm suggesting that we disembark and find a taxi driver (van tour) willing to give us a couple hour tour around the main points of interest for grabbing some nice photos and hearing about some history of the island, then allowing us time to walk on a beach or two and get our toes wet, then finishing up with some shopping before getting back on the ship by 1pm. (Shopping being the least important part.) Doable? Would it be better to take the tram up the hillside for some photo ops then try to get a taxi from up there? We've all agreed not to take an excursion through the cruise line. We're going to "wing-it", but I'm trying to avoid the indecision time and have something a little more firmed up in my mind prior to disembarking... Thanks for thoughts! Vakay

I posted a list of taxi/tour drivers in another thread so here's where you can find it.

http://boards.cruisecritic.com/showpost.php?p=52057331&postcount=33

And here is a list of things you can do in town other than shop.

http://boards.cruisecritic.com/showpost.php?p=52026212&postcount=3