first return flight back to the US. About 45 mins or so into the flight we hit some severe turbulence that seemed like it was tossing the plane around pretty good. The flight attendants stopped drink service and strapped in we were pitching so bad. It was like a boat it rough seas. Never seen a big plane tossed around like that. The pilot tried climbing up out of it and then tried descending. It was well over an hour before we were out of the worst of it. I was white knuckling it for a while there.