In the underwater caverns on Maui, I saw drawings of the ancient Hawaiians wading waist deep in the rivers with one hand out straight & one hand behind their backs waiting to signal their fellow hitch hiker to follow as soon as a river porpoise snatched the fish out of the out streched hand. At that monment when the porpoise was engorged on fish the 2 Hawaiians would swing over onto the fishes back & ride down stream to the river's mouth at which point they'd take a dive otherwise the fish would take them across the channel to Hilo. In those days no one wanted o go to Hilo, not even Johnny, it was the southern most place & at the end of the chain. The "hitch" part of the word derives the knots that the Hawaians used to tie themselves to the porpoise with (this knot they passed on to passing sailors which in later days became a famous knot of many types) & the "hike" part of the phase is from the actions they would make to the grass dresses when they would be mid stride in their jump to ride the fishes back. They'd hike up their skirt & jump.
So Sins, I'd date it back to the Poly mygrate son of 275BC.

Barry