INTERNET'S WILDEST RIDES.

Byline: Elizabeth Lee Cox News Service

``Desk chair'' adventurers have climbed to the top of Mount Everest and have peered at the remains of the Titanic, 2.5 miles deep in the Atlantic Ocean.

By reading online chronicles, they've shared in the excitement and eventually the tragedy of ill-fated Everest expeditions, and the frustration of the failed efforts to raise the hull of the Titanic. The Internet has proven an apt medium for adventure travel, conveying news and an array of resources with immediacy.

Now, online users can dip their toes into rafting trips through the Grand Canyon and a 250-mile-long canyon cut by Ethiopia's Tekeze River. Discovery Channel Online, which chronicled the Titanic salvage excursion, is sending biologist and writer Jim Malusa down the Colorado River on a 16-day, 280-mile journey that began Thursday. Mungo Park, a new Internet adventure magazine from the Microsoft Network, this week began publishing accounts of the Tekeze trip, expected to wrap up Sept. 27.

Paging through the sites this week brought up reflections on the trips to come, maps and educational resources - geological information on the Grand Canyon and a history of raft-running on the Colorado River, and history and wildlife backgrounders on Ethiopia. Look for accounts of the river journeys, supplemented with photos. Expect regular, but not daily, updates.

Malusa, who has written about biking across Australia for Discovery Channel Online, will be answering e-mail from viewers throughout the trip and will talk about the journey at 4 p.m. Sept. 26 on the Web site.

Biographies of team members on both sites state their previous experience in running rivers, which may quiet concerns by those who read the online chronicles detailing the deaths of guides and inexperienced climbers in a blizzard on Everest. But the dangers of the excursions aren't disguised, even on the Colorado River, where guided raft tours are a common sight.

``It seems that whenever I'm scouting a rapid, a guide shows up and not only tells me the best route, but also what happens if you take the wrong route, a conversation that usually ends, `And they didn't find the body for two days,' '' Malusa says.

The Tekeze River chronicles dance with the lure of the exotic, from the list of travel hazards (raft-eating crocodiles and hippos, land mines, malaria) to descriptions of the terrain. ``Locals swear that no one, native or Western, has ever passed through some of these basalt gorges,'' writes expedition reporter David Roberts. ``The whole place seems to have a taboo about it: The nearest villagers refuse to enter into its dark corridors, which teem with wild baboons.''