Excellent place went there for all the things you mention. Stayed at the Galley Bay on the East coast, this is more sheltered and good for snorkelling. The sailing trip we took went down the west coast for better wind or whatever the nautical term is.
The capital, St Johns is fairly small but has a handful of good restaurants and bars. Pre book a taxi with your hotel for your return in the evening as it can feel a bit dodgy after dark.
There are plenty of trips and sightseeing opportunities and you can take a trip to the other islands nearby. All in all I would really recommend it and would return again tomorrow if funds allowed!