The rope flung up because it's real. The man landing in the water could have gotten up there a number of ways but to me it looks like he jumped since it never shows whats behind them and it looks like his trajectory has an arch to it like he jumped forward as if to hide whatever he jumped off of from the camera. Also look at the trajectory and speed of the 'person' on the rope launch, and then try to imagine matching it up with the trajectory and position of the falling man. They don't match up even a little bit, they aren't even close.
The people going to check if he's ok would be in on it, just like every other faked video.
The only thing that makes me wonder if it might actually be real is the fact that it seems to be a pretty pointless video. OP could have course been trying to make a viral video for the money or for the sake of it, but usually the larger faked videos are made as some sort of ad. That being said, literally everything else about this video screams fake, from the cuts at literally the most convenient half second in the video, to the shaky camera and potato quality, to the superhuman acceleration even jet pilots would black out from, to the mismatched trajectory and landing, to the camera work that's so bad even a jet ski doesn't make it reasonable, to the funny shape of the 'human' being launched, and the delayed scream etc.
Could it still be real? Maybe, but it certainly doesn't do a good job of looking the part. This would be a good one to send CaptainDisillusion.