I was on that trip last February, although I don't recall if it was a full or half day. It was both fun and un-nerving at the same time. We thought this would be a kayak tour circumventing St. John and visiting several bhays but instead we headed out across the wide body of open water for several very small islands between St John and St Thomas. The water was choppy - I've kayaked before but was uncomfortable in such swells. The leader of the tour went way ahead of us - too far as much as I was concerned. Coming back was very difficult given we were tired and the choppy water. However, the snorkeling where we were taken was the best we saw around St John. If you go - be sure you understand exactly where you're going - open water, bays, shorline, etc. and how long you will be kayaking versus snorkeling and if you're comfortable with that then go and have a great time. Bring sun block and a hat.