As the Continental jet banked for a turn into the landing pattern, I looked down from my cabin window to see a long runway bordered on two sides by a clear blue Caribbean Sea and a fringing reef line of spur and groove formations. It looked inviting and I wondered what the diving was like. Little did I know that I would soon find out.

Our destination, the Don Juan Beach Resort, is not only the closest resort to the airport, it is also adjacent to one of the country's premier dive areas, La Caleta National Park. This underwater preserve includes the large reef system that I had seen offshore of the airport runway, plus several noteworthy shipwrecks.

The next morning we meet our dive guide Andi at the hotel pier and board one of the dive center's smaller vessels for the short ride out to the reef. Our destination is a shipwreck named El Limon, a 69-foot, triple-screw steel tugboat sunk as a wreck dive attraction in the summer of 1998.

As soon as we drop into the water, I can see the entire wreck. She sits on a 65-foot-deep flat sand bottom like a toy boat in a bathtub. High-profile coral heads border the sand flat on three sides, providing refuge from storm surges.

El Limon has become a haven for small fish and other marine life. Finning past the wheelhouse, we pass through a mixed school of small blue-striped grunt and yellow goatfish. Other wreck residents include trumpetfish, blue tangs, squirrelfish, multi-colored wrasse and a school of sergeant majors. After exploring the tug's superstructure, we drop over the rail to look for bottom dwellers such as conch, peacock flounders and lizardfish.

Swimming into the overhung gloom of the stern, we attract the attention of a porcupine fish, which inflates in warning. Apparently deciding that we pose no threat, this big-eyed blowhard finally exhales and then follows us for the remainder of the dive.

During our surface interval, we move a short distance to our second dive site. The wreck of the Hickory also rests upright on a flat sand bottom some 60 feet below the surface. A 144-foot-long, steel-ribbed treasure salvage ship that sank in 1986, this intact vessel is now home for schools of vivid red blackbar soldierfish.

We peer into open hatches and companionways, each of which holds schooling snappers. Deeper inside the wreck and closer to the bottom, we encounter a large cloud of glassy sweepers, a species that prefers the dark shadows of coral caves and caverns.

During her 14 years of submersion, this wreck has accumulated a dazzling collection of sponge life and encrusting corals, in a marvelous profusion of red, orange and yellow hues. Most impressive was the amazing number of tube sponges, which covered Hickory's exterior in a coat of yellow and purple tubes.

In the days ahead, we explored more of La Caleta's underwater treasures. We lingered over shallow coral gardens, navigated massive spur-and-groove formations that ended in white sand plains, and hovered over outside reefs that dropped beyond the limits of recreational diving. Overall, we found the park to be blessed with an impressive collection of hard and soft corals, as well as a wide variety and number of fish life.

Remembering my first fleeting glimpse of these waters from the airplane window, I realized that reefs of La Caleta had not only satisfied my curiosity, they had exceeded my initial expectations.

Staying and Diving

Treasure Diver's is a PADI resort facility and the on-site dive operation for the Don Juan, an upscale resort property that provides visitors with an all-inclusive vacation experience. Walter Frishbutter owns and manages the dive operation with legendary German precision, and employs a multilingual staff of five. The shop operates four boats and offers a full range of dive experiences that includes reef diving, wreck diving and freshwater cavern diving.