We have both been to Tortola and St. Lucia (my favorite). I have been to Barbados, but it is a big island and plenty I have not seen. We have seen most of St. Lucia so maybe a beach or snorkeling trip for us. We were there for a week years ago and took a great trip on a catamaran which included the lovely little port whose name I cannot remember, but where they shot the first Dr. Doolittle movie and a visit to drive inside the volcano, lunch and drinks. It was really fun. Castries the port is very interesting and not too far from where the ship docks. I particularily loved the main church which is very interesting and lovely with local art decorating it.
We know we want to go to the Baths in Tortola and there seems to be some question as to whether you can do it on your own easily because of the timing. We like snorkeling and are really going to rest and detox from our busy lives, so I don't think we will do that many whole island tours. My travel companion is on another trip right now and we will decide when she gets back. She has the excursion book so all I have is the names without descriptions. Some people have arranged their own tours of the other islands, at greatly reduced costs, and are looking for others to join them, so if we are on the island for a long day, we may do that. I leave for a family trip on Thursday, driving a car back from CA, and one of my goals is to sit down every night, research, and narrow it down, and book them.
I am not so sure about whether we are really going to Greneda or not -- our tickets say St. Vincent and people who returned from the first of the NCL 9 day cruises went there. No word on whether that will change back to Greneda by the time we go. There are some very positive reviews of this cruise on another board you might like reading. Some good hints and suggestions, plus other infor on restaurants, formal nights etc. There is also a thread with more people that this one.