THE POWER of the paddle meets the open water Saturday morning as the fourth annual Potomac Sojourn gets underway. This day- or week-long river excursion invites landlubbers and old salts to leave the workaday world behind and to get out and experience the Potomac River in a new way.

Don't expect a lazy river idyll: There will be no motors or sails to float your boat here, only paddle power when the small flotilla of canoes and kayaks takes to the water. The Sojourn's plan is to cover 80 miles in a week, traveling about 11 miles a day on the river and camping under the stars at night. Novice and experienced paddlers are welcome, with the opportunity to register by the day or to sign up for the entire week.

"Here's the great thing about paddling on the Potomac," explains Jamie Alberti, program coordinator for the Alliance for the Chesapeake Bay, which is sponsoring the Sojourn with the Interstate Commission on the Potomac River Basin. "Aside from the breathtaking views and amazing wildlife . . . you learn something new about the river every time you're on it."

And how long will you be on it? Before you worry about blisters and backaches, you should know that actual paddle time will be only about three to four hours a day, with plenty of breaks for educational programs. Sojourners will participate in water testing and habitat restoration, and there will be opportunities to tour local sights on land, as well as rejuvenating stops for swimming and meals.

"We've had children as young as 6 out there who did fine," Alberti assures. "It's great to see entire families out paddling along with experienced kayakers. There's always a good mix of ages and experience."

Paddlers meet and register at the National Conservation Training Center in Shepherdstown, W.Va., Friday and set up camp. (Shuttles are available from Virginia locations; see Web site or call for details.) Boats launch Saturday morning, setting a course for Antietam. Each day along the route brings a different destination and itinerary, with a full schedule that includes ghost tours, historic walks, lectures and campfire programs.

"Once people experience and enjoy the river, the more likely they are to get involved and protect it," says Steve Saari, watershed coordinator for the Interstate Commission on the Potomac River Basin. Saari believes that getting people out on the water, where they will learn about the river's resources and history, will promote its stewardship.

"Every year I see people come out, enjoy the river and take part in the educational programs," Saari says. You can feel the energy, people really come alive at the event. It's a wonderful thing to watch people get excited about the river."

2005 POTOMAC RIVER SOJOURN -- Shepherdstown, W.Va., to Great Falls. July 8-16. 301-984-1908, Ext. 113. www.potomacriver.org/sojourn.htm. A weeklong paddling trip along the Potomac River. Drop-in day paddlers welcome. Canoes and kayaks available -- see Web site for a complete list of recommended rental outfitters. $35 per day registration fee includes T-shirt, boat decal, river guide services, educational programs, camping fees and shuttle service to parking. Directions to each day's sites can be found on the Web site or by calling the information line. Camping with the group Friday is recommended to ensure departure time.

The Potomac Sojourn will push off Saturday morning, taking paddlers on a week-long excursion on the river via canoes and kayaks.Paddlers on the Potomac Sojourn will travel 80 miles from Shepherdstown, W.Va., to Great Falls.