USVI-On-Line

Does anyone know how much the fare is on the water taxi from the Marriott to Cruz Bay? Also, which is the closest grocery store in route from the airport to the Marriott? Finally, we are wondering how many of you have rented a car and actually driven on St Thomas-we will be going to St. John at least 3 times and would like to take it on the car barge-what are those rates.
Guess what it boils down to rental or taxis
Thanks
mricco