This spot requires a boost onto the yellow piece holding the container up, and then a very lucky, donator only jump to the ledge i have marked. Also, once that crate is dropped into the water by pressing the button across from it, you then have to boost on the other crate and jump across to it. You can also curve jump from the pipes on the right, but even then if the player shoots the zombie even in the chest, they'll just drop straight in the water. You could also get 2 players up there, making it 100% impossible for zombies to stab the player. I think it's a way to cheap ledge spot.