I'm taking a cruise, but would rather not give details. They have canned bus tours, but there are places I'd like to go that aren't on the itinerary. So, I'm looking for a taxi or guide service.
wackyD
How much time will you be at the port of call?
Santo Domingo is a good 2 hours, at most 3 hours away from La Romana (depends how fast one goes, although after San Pedro de Macoris things speeds up quickly).
If you have sufficient time for a round trip drive to and from Santo Domingo and at least 3 hours to see the historic sites at a brisk pace, then go ahead and visit the city. If, however, you have any doubts of the feasibility of such sidetrip while on shore, then focus on visiting other attractions near La Romana itself. La Romana is close to some interesting attractions, some natural and others man-made, but all are interesting.
-NALs