Vacation time? Put down that margarita and do something useful. Citizen Science Projects lists volunteer-hungry ventures in astronomy, ecology, geology, and meteorology. The Audubon Christmas Bird Count takes place every winter. The American Hiking Society runs trips for volunteer trail-builders. The Appalachian Trail Conservancy wants participants for a variety of projects. Cross-Cultural Solutions sends volunteers around the world to teach English, work in orphanages, and share professional skills. Volunteer Adventures trips include wildlife and conservation projects. History Travel sends travelers to dig for dinosaur bones in Montana and China. VolunTours focuses on Mexico's Baja Norte region.

REEF
The Reef Environmental Education Foundation organizes around a dozen field survey trips a year for certified scuba divers. Trips are also open to snorkelers. My St. Vincent trip cost $1,350, based on double occupancy, including lodging and breakfast for seven nights, up to 13 scuba dives, and a $300 fee covering REEF costs. The price of the trip for a nondiver was $700.

Flying
To get to St. Vincent by air, you must transfer on LIAT via Barbados, Trinidad, or Puerto Rico. For $956 I booked a round-trip journey from New York City via Trinidad through Travelocity that combined LIAT and American Airlines flights.

My return trip was a comedy of errors that included a 24-hour delay; a stint in a barbed-wire-encircled, broken-windowed Trinidadian guest house; and flights that left three hours late and seven hours late, both on American Airlines.

Next time, I'll try flying via Puerto Rico, which has more connecting flights to the U.S. mainland. Or I'll sail in—St. Vincent and the Grenadines (the country's full name) is gorgeous cruising territory.

Diving
Bill Tewes' Dive St. Vincent, REEF's partner for my trip, also offers dive packages, daily two-tank dive trips, gear rental, snorkeling tours, and day trips that combine diving or snorkeling with lunch and above-water sightseeing. Dive St. Vincent doesn't offer certification courses, but it does offer resort dives—in which beginner divers are allowed to dive under close supervision—and check-out dives, which are the final step in an open-water course.

In New York City, Panaqua offers courses and sells and rents scuba gear.

Hotels and Restaurants
We stayed at the Mariners Hotel in Villa. It's pretty and tidy and set on the waterfront around a palm tree garden, a terrace, and a small swimming pool. It's also home to the excellent but pricey French Verandah Restaurant. There isn't much to do in Villa on foot—it's essentially a strip of hotels on the island's main road—but you can walk from the Mariners Hotel to Dive St. Vincent and a few waterfront restaurants. One is Xcape, which is lively, casual, and relatively cheap and is frequented by locals and the occasional yachter.

Books
I couldn't find any guidebooks exclusively about St. Vincent and the Grenadines. I brought with me Rum & Reggae's Caribbean, Fifth Edition, by the irreverent Jonathan Runge.

For a spectacular look at reef life around the world, pick up photographer Jeffrey Rotman's new Underwater Eden: 365 Days. If you haven't taken up scuba diving yet (or want to convince a recalcitrant would-be dive buddy), a few hours with Rotman's close-ups and wide-angles ought to persuade anyone.