So i did this earlier, totally by accident. And thought, this would be cool to see how people go with it. Unfortunately no video of mine.
During the quest to leap into various bodies of water in Eastmarch, when you jump off the bridge you do a bomb. Now i jumped off the bridge on my horse, at an angle and hit the land on the side and it looked like a sonic the hedgehog spin into the water from there. Can you do this and post it? Now one thing, if you jump too far you will land on the ledge instead of bounce off it. My deliberate attempts have unfortunately landed me a little too far to bounce into the water. the ledge you want to bounce off is on the southern side of the river.