First time for us (man & wife) taking a cruise, we were wow'd every single day - getting to small places big ships don't/can't go, being flexible enough to proceed under sail (with ample power assist if chosen) rather than always under power, swimming off the side of the ship (100'+ long), getting to know crew and fellow vacationers (crew of 6, + 6 staterooms which were fully booked, so 12 passengers), snorkeling in bays and coves if you wanted to, bask if you didn't. Great, great food but not a glutton's thing, more like fresh island fruit at every meal, differing main course selections mostly with island flair, rum punch along with afternoon hors d'oeuvres daily, included in the price is all the beer/wine you want to pack away (but except for one "Culture Walk" evening [read bar crawl], I didn't see a single passenger appear to be under the influence). Plenty of sodas, water, juice, of course.
We worried about June "off season" & were met with almost perfect weather (one rainstorm all week, and that was short), not too hot, and with a choice daily of swimming here, walking there, sleeping in if you like - they'll launch the dinghy for just you if you want to go separate, but the attitude of all the folks on the trip was such that we all quickly became friends - no cliques formed, no cross word heard for a week - by anyone!
Can I give it 6's on a scale of 0-to-5?
You don't need to deal in Eastern Caribbean Currency, since everywhere takes U.S. dollars - just arm yourself with lots and lots of ones and fives and tens, since there are places that will struggle to break a $20. Exchange rate is 2.71:1 EC to US, and you should bargain in the local places to get initial prices lowered.
If you're looking to shop at fancy places in port, get your money's worth in calories at the midnight buffet, gamble in the casino, watch a floor show, or wear something other than a bathing suit and t-shirt on most days, this is not the one for you. Take one Hawaiian shirt for the fanciest dinner they have, leave the long pants at home, take loads of sunscreen & reasonable amounts of insect repellent, and expect to enjoy!!
I rated entertainment below 5, since "entertainment" is not part of the concept - that said, I rated it pretty high because I didn't want to be entertained.