Just got the game and noticed a Zombie agro on me from lightyears away. Chuckled and figured I would jump into the water off of a dock and swim away thus loosing the zombie and continuing on.
To my surprise I (hillariously) found that I simply fell through the water and hit the bottom thus breaking my legs. I could stand up, try to walk, and then fall to prone again as normal with broken legs but with no indication of drowning until my screen just went to black with "you are dead"
I died laughing but it seems like something that may need tending.