Scuba Holiday Heaven. Scuba diving off the barrier reef at Half Moon Caye. (SUN/Darryl Emerson)

AMBERGRIS CAYE, Belize -- When the turquoise waters become deep blue, you know you've arrived in heaven. You're at the Great Blue Hole, a world-famous dive site popularized by Jacques Cousteau.

On the surface it looks rather ordinary -- 1,000 ft. wide and 400 ft. deep. Once under the water, though, you know why you spent two hours on a boat to get here.

As the divemaster gives a briefing, excitement gleams in the eyes of divers, like kids at an amusement park. After donning a wetsuit and scuba gear, you jump in and descend into wonder.

Almost perfectly circular, the coral in the Hole is simply breathtaking. At 100 ft., the wall gives way to a deep undercut. At a depth of 130 ft. in the dimly lit cavern, you can clearly see stalactites meeting stalagmites. Some are so large that two divers could not join their hands together around them. It's amazing to see them silhouetted against the blue glow of filtered light coming from beyond the ledge where a few bull sharks lurk curiously in the water. No wonder this dive site is world famous.

Soon, it's time to surface, but nobody complains. Spots like this are why everyone comes to Belize: To experience the world-class diving.

After an hour on the surface, it's time to visit Half Moon Caye, said to have the best diving in Belize, in part because the waters abound with marine life. Our group dives in and we follow a gentle slope of powder white sand leading to a mountain of coral that forms a long ridge.

Along the way, we spot huge southern stingrays and majestic eagle rays, crisscrossing the sand in search of food. Along the reef, we encounter large jewfish, groupers, angelfish and parrotfish.

Near the end of the dive, we watch as a large wing-tipped manta ray in full flight gracefully swims by. It's another rare sight, yet common in Belize.

During our return to shore, we're in for another treat -- The Elbow, located near an offshore atoll. A sheer wall beginning at 30 ft. plummets to a depth of more than 2,000 ft. It's graced by a strong current, which brings large fish and is what makes the dive so spectacular. Schools of horse-eye jack, pompano, Bermuda chub and yellowtail snapper cruise the reef with Caribbean reef sharks and huge groupers. After a trip through one of the deep cut crevices , it's time to call it a day.

Belize is a truly unique country in the heart of the Caribbean Basin, bordering Mexico to the north, Guatemala to the west and south, and flanked by the Caribbean Sea to the east.

Our destination is Ambergris Caye, reminiscent of Greece in the '70s. Protected by the largest barrier reef in the western hemisphere which parallels its eastern shore, Ambergris Caye is the capital of carefree and casual.

San Pedro Town is dotted with seaside restaurants along the waterfront. Wooden stools at rustic bars are filled with visitors and ex-patriots sipping on cool drinks and exchanging chatter about their day of diving. Others express the enjoyment of just chilling out at the beach, or in a hammock under a shady palm tree.

Almost everyone who ventures to Ambergris Caye comes to Fido's at least once and most return. I was there every day. It is built around a rustic palapa and is a great place to meet and mingle with people from all walks of life. Millionaire ex-patriots sit side by side with tourists and locals. The sign in the hotel lobby says, "No shirt, no shoes, no problem." That pretty much says it all.

The best pizza is found at Ambergris Delight. For a casual burger or chicken wings, try The Barrier Reef restaurant where the Chicago-born owners try their best to rival the world-renowned Buffalo wings.

Budget-minded travellers should try Los Cocos, where the sand floor creates a unique atmosphere. The menu changes every day. One thing they never run out of is key lime pie; it's the best money can buy.

On Tuesday night, the Pier Lounge hosts a "chicken drop." For a dollar, you can buy one of a hundred squares. Once all tickets are sold, a chicken is placed in the pen. Whatever square the chicken "drops" on is the winner. The holder of the winning ticket must then clean up the mess.

Party goers will enjoy Tarzan's, which can be a little rowdy at times but is always fun. Across the street is Big Daddy's, which looks like a South Pacific resort and is where most of the action is until the wee hours.

The streets of the town consist of sand over a layer of concrete. Barefoot is definitely the way to go. While strolling the streets, you'll find many souvenir shops filled with handcrafted jewelry and owners who greet everyone with a smile. Remember: No shirts, no shoes, no problem. That just about sums up Ambergris Caye.

If you go:

GETTING THERE: Continental and American have daily service to Belize City via Houston. Maya Island Air offers eight flights daily between Belize City and Ambergris Caye, starting at 9 a.m. and departing every hour.

MORE INFO: Belize Tourist Board, 421 Seventh Ave., Suite 1110, New York, NY 10001. Phone 1-800-624-0686. Web site: www.travelbelize.org.

ACCOMMODATION: The Sunbreeze Hotel is centrally located at the end of the main street in San Pedro. The on-site dive shop can arrange all island activities, including scuba diving, snorkeling, fishing and trips to the mainland. Rates are US$120 per night for a standard room and US$150 per night for a deluxe room with has a Jacuzzi bath. For exclusive dive packages, call 1-800-688-0191 or e-mail sunbreeze@gate.net.