I'm assuming you'll go to the Tobago Cays, because they are pretty essential in terms of spectacular snorkelling and diving. If you are, I would recommend an evening on Happy Island - it's basically a sand bank off Union Island, which has been built up with conch shells. The guy who owns it will pick you up from the jetty, serve you with killer rum punches while he cooks dinner (usually lobster or somesuch grilled over a wood fire, simple but delicious). You can relax for as long as you like in the hammocks, before he takes you back to Union Island - definitely a good experience. If you are going further north, up to Bequia - well the drinking scene is very lively there, particularly around Port Elizabeth, but I would say the best and most interesting restaurant is Fernando's Hideaway. It's West Indian, a limited menu (perhaps 3-4 choices of mains), but very, very good, mainly due to the interesting side dishes. They don't open every night, and get extremely busy (booking essential), so you'd probably have to share a table, but that usually works out well. I've always been disappointed by anything with pretensions to fine dining in the Grenadines, but have no experience of Grenada, which is where you are more likely to find something good along those lines. I have a feeling Gary Rhodes has a restaurant there.