Dynamic Rigging

I am looking for help with a dynamic character that would allow the figures on the raft to dynamically react to the raft’s motion on the water. Meaning I don’t want to keyframe their swaying to the raft motion, just react to it based on the physics of the moving raft.

Can someone maybe point me to a tutorial or Unreal documentation that would address this? I am using Cinema 4D to creat the figures if that helps.