Deep sea diva: Rebecca Hunter holds her own under water.

Her logbook reads like the diary of a National Geographic adventurer: "battled murky waters in Fiji, trailed spotted eagle ray in Belize, encountered hammerhead shark in Egypt." These are modest jaunts compared to Rebecca Hunter's dive last August to the Henrietta Marie, a 17th-century slave ship sunken off Key West, Florida, which she called a spiritual experience. "We located several of the ship's cannons in the sands; to know that our history and our story lay in those very sands was an awesome reality."

Hunter, 43, a radiologic technologist and sonographer in Oakland, California, took a discover scuba course while on vacation in Puerto Vallarta, Mexico, in 1997. She has since become a certified advanced open water diver and has logged 144 dives, achieving her deepest dive at 105 feet.

Certification is the first trial every diver must face. "Dive shops require you to be a certified diver before they take you out," shares Hunter. Rescue diver, dive master, and instructor are the certifications available. Specialty certifications include wreck diver, underwater photographer, and search and rescue diver. Hunter aspires to attain rescue diver certification.

Scuba diving is an adventure sport with inherent risks to consider, particularly for those with heart and lung conditions, anxiety, or claustrophobia, says Hunter. "One major hazard is decompression sickness, which occurs when too much nitrogen enters the body. All dives require a slow ascent, a 'safety stop' at 15 feet to release nitrogen, and a surface interval [out of the water] to release nitrogen between dives or before flying. Excess nitrogen in the body can cause fatigue, numbness, and death."

A member of the National Association of Black Scuba divers (www.nabs divers.org), Hunter adheres to all necessary precautions. She averages 20 to 25 dives a year. Hunter remarks: "Interacting with the sea world is a calming experience."

GETTING STARTED

Costs An open-water dive course, which includes a tutorial, pool sessions, ocean dives, and materials, can cost $300. Snorkeling gear such as a regulator, mask, fins, snorkel, wetsuit, and buoyancy control device costs $800 to $1,800. "Tanks and weights are usually included in the cost of a dive [$65 to $100] but can be purchased individually."

Acquiring Certification Agencies that offer courses and certification: Scuba Schools International (www.ssiusa.com), Professional Association of Diving Instructors (www.padi.com), and National Association of Underwater Instructors (www.naui.org)

Dive Guides Two helpful guides are Scuba Diving: A Woman's Guide (McGraw-Hill; $14.95) and The Diver's Handbook. The Complete Guide to Your Own Underwater Adventures (Globe Pequot Press; $24.95). Popular periodicals include Scuba Diving and Sport Diver.