The CannelU found their share of hidden sand bars in unexpected spots. They spent time shoving off, wading, and restarting motor, put this kind of scenery (right) compensated for minor upsets.. .. - ,.-.. - .lil-i.:. The Wildest Picnic in the West v. This annual family cruise down Utah's Green and Colorado Rivers combines camping and boating with rugged adventure and spectacular sight-seeing Photos and Text by ROBERT P. CROSSLEY YOU BOUNCE over 196 miles of twist ing, churning river channels in a 17-foot outboard boat A sand bar sud denly looms up and sheers your pro peller. Still you're luckier than another "picnic boat" which ran aground on a sand bar and had a waterway speedster smash into its rear end. You're warned not to turn down one river its treacherous current will shatter your boat and suck a person under water. Craggy cliff's rise abruptly 2,000 feet, and there's only one way out of the canyon in your trusty, bouncing boat. Sounds like a harrowing voyage, and it is, but the Merlin Cannell family found it literally a picnic They trailered their boat 600 miles from their home in Grand Junction, Colo., to Green River, Utah, where they joined 517 other boating camping families in last year's Friendship Cruise down the Green River and up the Colorado to , Moab, Utah. (This year's cruise is being held this ' weekend.) What are the attractions of river picnicking to Merlin and Bertha Cannell and their three teen agers, Karen, 16, Shirley, 14, and Gary, 13? Well, first there's the good fellowship of other families with like interests, and there's neighbor liness, too for example, firemen of the local towns drove all the cars and rigs to the terminal point, Moab, where the boaters picked them up. The Cannells and their friends also found spectacular scenery: granite canyon walls that dwarf men and boats and pastel desert ex panses that change colors from misty dawn to fiery sunset. Each twist in the river turned a page of history: an Indian fort still preserved in the desert aridness, the old prospectors' canyons with such names as Hell Roaring and Horse Thief. Excitement came in the rough but navig able rapids, and in the stretches of calm, boaters made their own excitement by water skiing. THE friendship cruise wends its way 128 miles down the Green, then 68 miles up the Colorado. In the evenings families pull into quiet coves, unpack their picnic gear, and appease ravenous appetites with campfire-cooked meals. They can hear singing from camps up river, and there are tales about the day's experiences but not for long. Soon they are asleep, getting rested for a dawn call and more adventures on the wildest picnic in the West. On a stretch of calm, Karen Cannell takes to water skis. Brother Gary watches from stern. family Wnkly. May It. IM1