How do you get past the small pond with the crate in Chapter 4?
Drag the crate backward a few feet until it's underneath a hanging rope. Climb the rope and make your way up and through the trees, until you reach the far upper right corner of the forest. Here you'll be able to push over the top of a dying tree, giving you a longer bridge to push into the water. Use that along with the crate to cross the gap.
Here's a video of the process: