The Ultimate Skydiving Experience

Where: Lumberton, Mississippi, U.S.A.

If you want to get high, really high, try HALO jumping out of a DHC-3 "super otter" airplane at more than 30,000 ft. (9,000m) above the earth's surface. That's the cruising altitude for most commercial airlines, more than 305m (1,000 ft.) higher than Mt. Everest, and almost six miles from the ground.

HALO stands for a High Altitude, Low Opening parachute jump, which the US military has been using for years as a way to insert Special Forces into enemy terrain. Using this maneuver, troops can drop stealthily because their aircraft is hidden by the clouds, invisible to ground-level observers, and looks like a commercial plane on radar screens. The technique was first used in combat during the Vietnam War, though its development began during the Cold War. But it's a relatively new adventure for adrenaline-seeking civilians, and currently the world's highest parachuting experience available to them.

At this jumping altitude of 30,000 ft., the temperature is somewhere between -25 and -35°F. You only have about 30 seconds of useful consciousness before blacking out from the lack of oxygen and risk severe brain damage or death from hypoxia. Not to mention, of course, there's the obvious risk of death if your parachute malfunctions. You must be in excellent shape, go through a full afternoon of training, and wear a specially fitted oxygen mask for the duration of your entire journey -- up and down. Even though you'll be taking a leap in tandem with an expert jumper, you'll need to learn some skydiving basics and practice pre-breathing techniques. (For instance, you'll need to breath 100% pure oxygen on board the aircraft to prevent the sort of "bends" you can get while scuba diving if you're not careful.)

After you take off into the sky, try to ignore the waves of adrenaline crashing over you, and keep breathing calmly to get that adequate oxygen supply. When the jump master finally gives you a nod, get ready to exit. Depending on the weather conditions, you'll free fall for about two mind-boggling minutes before releasing your chute and settling into a floating mode. The earth will appear in patterns and colors far before you can make out any detail of the landscape. But this jump isn't really about appreciating scenic views. It's just about jumping out of a plane as high as you can, and enjoying the outrageous experience of having a GI Joe fantasy come true.

Information: Incredible Adventures (tel. 800/644-7382; www.incredible-adventures.com)

When to Go: May-Nov.

Getting There: Gulfport-Biloxi International Airport or Louis Armstrong New Orleans International Airport.

Where to Stay: Hilton Garden Inn Hattiesburg, 133 Plaza Dr. (tel. 601/261-3770; www.hiltongardeninn.com).