It's the world of scuba diving -- strapping on a tank and equipping yourself with the proper diving equipment to explore all that the world of underwater has to offer.

For those living in the cities of Dallas, Houston and Austin, exploring the world of scuba diving may mean traveling to the coast of Texas, along the Gulf of Mexico. But there are also numerous opportunities inland, with training facilities, including one in Athens, southeast of Dallas, available for training and recreation.

Those choosing to take up scuba diving will have lots of company, with an estimated 3 million Americans now certified scuba divers, many of them Texas residents.

While there are scuba diving possibilities in and around Texas, including the shores of the Gulf of Mexico, many scuba enthusiasts head to the warm waters of the eastern and western Caribbean, where coral reefs and marine life are aplenty. Some opt to stay at one or more of the hundreds of land-based resorts from which they can dive -- or learn to dive -- but many divers will want to stay on a boat, either crewed charter boats (in the eastern Caribbean) or live-aboard dive vessels (in the western area).

On a dive boat the crews are diving professionals, many being instructors who can help with a new diver getting certified or checked out if it's been awhile since a person's last dive. Charter captains know the most popular dive spots and have a few not-so-well-known favorites of their own. All of the boats have dive equipment on board and most have compressors to keep the dive tanks full.

Land-based vacationers may have to travel in a small open boat for an hour or more to get to a dive site, but those on a charter or dive boat are already there. Plus, they aren't limited to one area; they can dive from one island one day and another the next. Indeed, on a live-aboard dive boat in the western Caribbean, a vacationer can travel more than 100 miles over the water during a typical seven-day trip.

It's also often less expensive to charter -- with food and drinks included -- than to stay in a hotel or resort. Extras that hotels may tack on to a bill - - like rental fees for equipment -- are almost always included in the charter fee.

There are many options for learning how to scuba. Open Water certification, which includes classroom sessions, a pool dive where you learn to use the scuba equipment, and four open-water dives, can be obtained in as little as four or five days. An increasingly popular certification method is to take the classroom portion and pool instruction at home, and then have your instructor write a letter of referral to a dive instructor in the Caribbean.

In the eastern Caribbean, especially the U.S. and British Virgin Islands, there are at least 40 yachts available with a certified diving instructor so you can learn right on board. The kinds of boats available range from 80-foot motor yachts and sprawling catamarans to smaller sailboats that cater to couples. Each boat and crew is different, but they all want their clients to have a great time.

If scuba diving isn't exactly what you want, but you still want to check things out, snorkeling can be a wonderful way to get a window on what's below. In St. John, USVI, as an example, there is a marked snorkeling trail in Trunk Bay maintained by the U.S. National Park Service.

Another benefit of crewed charters is the ability to dive after the sun goes down. Some 80% of all marine life emerge only at night, but with underwater flashlights, a diver is all set.

Live-aboard dive vessel operators say a diver is four times more likely to see large marine animals like manta rays, dolphins and whales than they are staying at a land-based resort.

If you want more information on scuba diving, you don't have to go too deep. For a start, check out the NAUI, PADI and YMCA Web sites at www.naui.org, www.padi.com, and www.ymcascuba.org. Learn about Divers Alert Network (DAN), an insurance and medical program for divers, at www.diversalertnetwork.org. An excellent site for all-around information on scuba diving is www.scubadiving.com.[MSOffice1]

Scuba diving is one of those lifestyle activities that can energize those who try it. What can also be energizing is knowing you're looking after your long term health.