Pair Paddles : Across CountryWASHINGTON (AP) — Two men in their early 20s paddled a kayak into Washington’s tidal , basin Friday ending a six-month cross country trek by water.About 60 persons were on handat the basin when Jimmy E. Curnes, 23, of Wheeling, W. Va., and John A. Davidson, 24, ofCarlisle, Pa., turned their tiny craft in from the Potomac River. Among those present were their parents, Mr. and Mrs. Ray Curnes of Wheeling and the Rev. and Mrs. John Davidson of Carlisle.Curnes and Davidson crossed the country via water, except for portages in the Rocky Mountains and the Aileghanies.Their adventure started May 19 at Astoria, Ore., they paddled their tiny kayak up the Columbia, Snake, and Clearwater Rivers to Kamiah, Idaho.They carried their gear over the Rockies to the Great Falls, Mont., then paddled down the Missouri River to the Mississippi, up that river and Ohio and Monongahe-la. They portaged over the Alle-ghanies to the North Fork of the Potomac for the last lap to Washington.Curnes and Davidson said they got the idea for their trip while they were serving with the AirForce in Germany.Although they reported they were once swept over a falls in the northwest, caught in tornadoes and had to live off the land for three weeks while portaging the Rockies, they said their biggest challenge was paddling up the Ohio River.Curnes and Davidson estimated their trip cost them each about $450, They hope to recoup their expenses and help pay for college by selling articles and pictures of the trip. Curnes said he will probably go to a schQol in West Virginia while Davidson I leans toward Penn State.