How to create a water current that pushes a floating object

I am just starting to mess with unity. I am trying to simulate a simple water current that pushes an object in a given direction… like a river or rapids.

Is there a plug in that makes this simple? or is there a simple way of doing this?

Thanks

If your river has curved, place waypoints and get your boat/object from waypoint to waypoint.

More realistic, take the direction between the previous waypoint and the next waypoint and apply a force to the boat in that direction, that allows you to divert or even to go upstream. Also, if the river has a bigger slope, the vector will point downward and add itself to gravity so your boat will speed up naturally.

Remember to normalize the direction vector.