This is something l never tire of seeing. It's Lee Marvin in 'Paint Your Wagon', falling down drunk into the river. He does it completely straight backed, and by the look of it, that river is not very deep. Even if it was, it would still hurt, dropping down face first like that. Luckily for Lee, he was meant to be drinking heavily throughout most of the shoot, so he might not have felt the pain at the time.