Water motion instance?

I'm trying to make some realistic water without using the smoothterrain that slowly pushes characters, parts, etc if it's being touched and I was wondering if there's an instance that does this? I know it's possible because I've seen it in another game before. Basically what it did was while players were touching a part, they'd be slowly pushed back, and forth kinda like the water terrain. I've tried several methods(cframe, bodyforce, bodyvelocity) and none have had the same effect. Any advice would be helpful!