We rented a small powerboat 5 years ago on our last trip out of Cruz Bay and I remember the rental company giving us a map to get to Road Town I think to go through Customs. We made no previous arrangements, just did it the day we rented the boat. Everyone has to do it, no way around it. It did end up being pretty simple, we tied up the boat, came on the dock to the customs office, payed a couple of $$, got our passports stamped, and on we went. Took under a half hour I believe- but you do have to do it. We had no trouble finding the customs office. The rental company just gave us the map, nothing more, no more needs to be done by them anyway. Have a great time!!!

You can also clear customs at Jost van Dyke, in Great Harbor. Great Harbor has a small dock that will accomodate about half a dozen boats; otherwise, you would have to anchor and swim or dinghy in to shore. We motored to Jost last Saturday, cleared customs there, and then motored on to Cooper Island. The stop at Jost added maybe 8 miles in total to our trip to Cooper as compared to a stop at Roadtown (check your charts to be sure), but Jost is a fine destination in its own right. Foxy's bar in Great Harbor was closed for the season but Foxy was playing by himself when we walked over there, and sang four or five very funny songs for the four of us. White Bay, a few-minute boat ride west of Great Harbor, has Jost's nicest beach and is famous for the Soggy Dollar Bar. We were able to dock at Great Harbor, and you might also be able to do so, since you will be travelling in the low season. In the high season, I would not counting on being able to tie up at the Great Harbor dock.