If you're cruising the Southern Caribbean, it's time to get excited about diving and snorkeling. Some of the region's best spots for the sport -- Bonaire and Grenada spring to mind -- are there, as well as lesser-known Scuba spots like St. Lucia and Aruba.

If you plan on diving more than once or twice, it's worthwhile to bring your own gear if you have it; even casual snorkelers should consider bringing their own mask and snorkel for both fit and hygiene purposes.

Here are some of our top choices of places to explore life underwater.

Aruba

With steady northeast trade winds, Aruba's known as a windsurfing and kitesurfing destination. But it's worthwhile to don your wetsuit there, too.

The wreck of the German freighter Antilla, which lies in 60 feet of water, is the island's most popular dive site. Scuttled in Malmok Bay by its crew at the outset of World War II, the ship is one of the largest diveable wrecks in the Caribbean, and it's now home to tube sponges, hawksbill turtles, lobsters and plentiful fish life. Snorkelers note: The upper decks are visible from the surface.

Who It's Good For: Beginner divers and snorkelers will feel at home; there are around 30 named dive sites on the island.

Bonaire

Unarguably one of the Caribbean's premiere destinations for Scuba-diving, Bonaire established a marine preserve in 1979 that protects all of the island's waters, from the high-water mark out to 200 feet deep. It's shore-diving heaven, with the island's 63 dive sites marked by yellow-painted stones near the road. Another 26 sites ring tiny, uninhabited Klein Bonaire, just offshore and accessible by boat. At Salt Pier, ships tie up to haul the mineral to the U.S. for winter roads, but if no vessels are at the pier, the site is s a must. It boasts pilings patrolled by sergeant majors, tarpon and green sea turtles.

Who It's Good For: Everyone -- if your ship stops in Bonaire, you simply must dive. There are shore dives, boat dives and deep dives. Bonaire keeps the novices and the salts coming back.

Curacao

Right between Aruba and Bonaire lies Curacao, the largest and most developed island of the ABCs. It's a melting pot above water, with English, Spanish, Dutch and Palamentu -- a Creole language drawn from Spanish, Portuguese, Dutch, French, English and Arawak Indian. That diversity is represented beneath the waves, as well. The fringing reef system hugs the shore, so surface swims are short, and most dive sites are in the 60-foot range, meaning that even inexperienced divers can log at least 45 minutes of bottom time. You'll see plenty of macro-life like frogfish, seahorses and mantis shrimp at sites like Bullenbaai, but keep your eye out for rays and turtles, too.

Who It's Good For: Beginner divers will love the easy, sloping reefs; advanced divers should check out the wreck of the cargo ship, the Superior Producer, which sank in 1977 in 100 feet of water.

Grenada

Verdant Grenada offers plenty of variety: drift diving, an underwater museum and one of the Caribbean's most famous wrecks, the Bianca C. The sunken ship is known as "The Titanic of the Caribbean" because, at 600 feet long, it dwarfs other wreck dives in the region. A passenger liner, it sank in the St. George's harbor in 1961 with one casualty. The top of the wreck sits at 100 feet, though, so it's only suitable for advanced divers. For a casual diving or snorkeling experience, check out the Underwater Sculpture Park, much like the one in Cancun. Life-size human statues like "Vicissitudes" -- a circle of children -- are now beginning to host coral in 15 feet of water.

Who It's Good For: Divers, from beginners to those who are advanced, will find this area appropriate; so will snorkelers. Grenada has plenty of famous sites and shallow coral gardens.

Barbados

Barbados is known for Rihanna and rum (do not leave without taking a Mount Gay distillery tour), but there's a number of great dive sites on the island's southwest coast. Carlisle Bay Marine Park features six shallow wrecks, with depths ranging from 10 to 45 feet, which are all accessible on the same dive. There's usually between 40 and 70 feet of visibility on barrier reefs about 0.5 mile offshore, and they're home to frogfish, eels, reef fish and turtles. Folkestone Beach & Marine Park offers near-shore snorkeling in calm waters, as well as snorkel gear.

Who It's Good For: Novice divers and snorkelers will love the great visibility and easy dive and snorkel sites.

St. Lucia

Most of St. Lucia's best diving lies almost within the shadow of the island's most recognizable landmarks, the Piton Mountains. Below as above, the Pitons' steep slopes give way to underwater walls: Superman's Flight, at the base of Petit Piton, is covered with soft coral, while Piton Wall offers a dramatic drop-off where you'll see trumpet fish, filefish and schooling jacks.

Within the Soufriere Marine Management Area is the Anse Chastenet house reef, which starts in just five feet of water and is perfect for snorkelers, with plenty of parrotfish, blennies, morays and needlefish. Black-sand Anse Chastenet beach is steps away.

Who It's Good For: All levels of divers and snorkelers will enjoy this location.

Martinique

Martinique's diving is split into four areas. Precheur - St Pierre offers walls, wrecks and black sand, while Anses d'Arlet is a white-sand seabed, with a mix of rocky slopes and walls. Baie du Diamant offers some nice coral and great snorkeling opportunities; Baie de Ste Luce is home of the French island's most famous dive site, Diamond Rock. Offshore of Martinique's southern coast, the rock can present challenging diving conditions (watch for current), but there is a spectacular cavern extending from one end of the island to the other -- not for the novice nor faint of heart.

Who It's Good For: Novice snorkelers to advanced divers will do well there. Speaking French helps a lot on Martinique; it's difficult to do it yourself with English alone.

Dominica

Dominica is one of the Caribbean's undiscovered diving gems, and if you're lucky enough to dock there, you'll know why. The mountainous volcanic island offers plunging walls, bubbling sea vents, reefs, corals and a year-round pod of sperm whales. Scott's Head Pinnacle in Soufriere Scott's Head Marine Reserve is one of the island's most popular dives and begins with a swim-through that puts you face-to-regulator with soldierfish, grunts and lobster.

As for snorkeling, the Champagne Reef is a must, where you can swim through bubble streams created by volcanic vents on the sea floor.

Who It's Good For: Novice snorkelers to advanced divers -- and whale-watchers, too -- will love it there.

Guadeloupe

It helps to know French on the butterfly-shaped island of Guadeloupe, but even if you don't, you'll be able to communicate a desire to dive. With 12 named sites and three wrecks, the Cousteau Reserve is a good place to start for both divers and snorkelers. A little further afield (up to two hours by boat) -- and only for experienced divers due to changing currents -- is famed Sec Pate, a sub-marine mountain in the middle of the Les Saintes Channel. The peak is at 49 feet, and divers will find sea turtles, sea fans, healthy coral, gorgonians and plentiful fish.

Who It's Good For: Beginners to advanced divers will find this location ideal.

Antigua

The sheltered southwestern coast of Antigua provides the best opportunities for logging some bottom time. There's little to no current, and visibility can top 100 feet, so beginners and photographers will both be pleased. Cades Reef is one of the most popular spots for both diving and snorkeling; the fringing reef system offers a variety of sights and tons of life, including lobsters, stingrays, barracudas and turtles. Most dives are in 30 to 50 feet of water. Part of the shallow reef has been turned into the Cades Reef Antigua, perfect for snorkelers. Another good shallow spot is Fryers Shoal, a coral knoll, which sits in only 20 feet of water.

Who It's Good For: Novice divers and snorkelers will do well here.