Damn. This dude tries to jump off a pier into the harbor and had no idea how deep the water is. Like no idea at all.
Turns out it's about 1 foot deep. I feel like if you can't see to the bottom of water that's one foot deep that means it's nasty enough that you probably don't want to be in it (see Baltimore Inner Harbor).
There's a decent chance this dude broke his tailbone landing on his ass like that. I'm not even sure there is a proper way to jump into water that shallow and not hurt yourself in some way.
Somebody call an ambulance and get a tetanus shot ready.