What one of these lines should I choose for a Caribbean cruise. I like to visit ports but relax as well. My husband and I tend to keep to ourself but try to be sociable. It would be nice not to have to dress to the nines, but that's not a deal breaker for us. Any recommendations great appreciated.

Naveron,
You should visit Cruise Critic where you will find a separate site for each of these cruise lines. There are several threads where people compare them. After some research you will get a better feel for what might appeal to you. You can't go wrong (only broke) with any one of these.

On a personal level, my all-time favorite cruise experience is SeaDream. Silversea, however, is also outstanding though quite different, in terms of dress codes and more structure. I've never sailed Seabourn but hear only raves. You've certainly selected the top three and, I agree, no way you can go wrong with any.

Thank you both!. Judia, what did you like about Seadream over Silversea? Thanks

I noticed that you did not mention Regent. Regardless, there is an interesting comparison between a SeaDream Caribbean cruise and a Regent Caribbean cruise on the Cruise Critic Regent Web site. I think the OP also posted a review on the CC SeadDream Web site.

Of these three lines, Seabourn is the most dressy. I think it really matters what your interests are. In addition to Regent, perhaps you might also want to take a look at Oceania, another relatively small-ship luxury line.

Seadream is the most casual of the ones you mentioned. There is less to do on Seadream though and some people think it's too laid back with so little activities to do but relax. The food is not as good as Silversea or Seabourn if that's important. Silversea has the best cabins of the 3 you named. Not sure if you've tried Regent but for what you're looking for, this might be your best bet, it has the best of the above 3 rolled into one.

But isn't Regent a larger cruise line? About 700? I would prefer small unless you think it really doesn't matter.

Yes, Voyager and Mariner at FULL CAPACITY with 2 in a suite hold approx. 700 but from my experience there are many single travelers with 1 in a cabin. I've never felt crowded on either of these ships, plenty of space for everyone. I can't wait to try the new Prime 7 restaurant on both of these ships. It's compared with Morton's with lots of various steaks, prime rib, surf & turf, fish (including Dover Sole), ribs, etc There is also Signatures which is French cuisine., LaVeranda is usually more an Italian restaurant. I guess I like the dining choices best on these 2 Regent ships. Oops...I just realized that you said Caribbean. I don't think the Voyager spends much time in the Caribbean.
The Navigator spends time in the Caribbean but doesn't have Prime 7 or Signatures.