It is possible to let an arrow pass through the floor. This is useful in order to open the path from Inkwater Marsh to Kwolok's Hollow without draining the water. To do so, you want to hold Bow in order to charge an arrow (this won't work if you have the shard Quickshot equiped) and then pause the game on the frame when the arrow is shot. You can use the weapon wheel in order to both pause the game and pause buffer. To make the pause buffering easier, open the weapon wheel while holding Bow, then release Bow. Finally, release the weapon wheel for a really short time and press it again right after. Repeat the last step a few time until you can see your arrow being shot. If you prefer, you can also bind a second weapon wheel button, which can make spamming it easier.