For some reason, I feel as if sentiment towards Water is notably lax around these forums. I just seem to be consistently reminded of it for some reason.

 I surely don't know why. *Eye Flutter*

 Now, now, I agree. Drinking some cool, refreshing water is quite enjoyable. It is the Lifeblood of the Planet Earth.

*Blatant pause & clearly distinguishable cluck of the tongue.*

 It's very important to Humans.

 But that's sort of the... Thing.

 You know the old adage: That which giveth, Can taketh away.

  Now, I acquiesce. I am sufficiently biased here. I once had to watch a small puppy drown because there's not much CPR you can do on a young pup barely six inches long. Bit of a... bad time, I'm sure one can agree. ...but I do not disparage others of their own enjoyment of the Watery Arts.

 I used to enjoy swimming an awful lot as a youngspawn. It's relaxing, ain't it? Somewhat of a practice in Sensory Deprivation, eh? Floating weightless, eyes & ears closed, away from anything the body can touch. As if the world didn't exist. But... but I do seem to recall Sensory Deprivation driving some test subjects insane. Me? Floating like that gave me this odd sense of a shark somehow appearing in the pool from nowhere to gobble me up whilst my guard was down. Found it a bit hard to stay relaxed,but I am rather high-strung.

 Clearly.

 Anyhow.

 I wish not to depress my audience with tales of drowning.   .... No, how I DID want to depress you was with what, specifically HAPPENS when you DO drown!

 See, do stretch your imagination with me here. A Hypothetical of sorts. 

  See, The human body is basically one big bag of Squish. If you have access to a human body right now, turn one on its side. Many of its internal organs will just flop over to fit gravity. Sometimes you can even hear it fall over or even feel it tumble inside, if you focus on it. On this, a planet dominated by Water, the dominant lifeform had to basically evolve to contain as much goopy water as physically possible. Humans are squishy FleshSacks.

 Weird, INNIT?!!?

 But that's the thing, though. The human organism needs more than just water to survive. Otherwise, it'd be a pretty jellyfish! It needs to take in the labors of the Earth, but more importantly for our example here, a respiratory system to take in Air. To help with such, the Human Body has specially designed orifices to obtain said element of Air. If a creature dependent so on Air finds itself engulfed in Water (Which, of course so dominates the planet Earth to an extent where it pools together in piles so deep that no living culture on the planet has ever explored deep enough to see the entirety of its encompassing mass.) it naturally closes off the passageways that don't require that much Water getting in. However...

 That time is limited.

 Eventually... the mouth has to open. Because if even it doesn't... the water pressure will force it open.

 So, at some point, Water will invade the organism's body. Force itself down orifices it doesn't belong. Because that much water would severely damage the human specimen. And clearly, an imbalance of too much of one element will prove detrimental to the creature.

...

 But literally choking a creature to death isn't enough. Water seeps in through the skin, through every tissue it can. Given enough time, Water will find its way into anything it can, even rock or steel. Water is, after all, known for its Malleability. Even partially submerged for, say, baths, a human body will start absorbing water into itself. The skin will puff up with the excess of Water. And, given long enough time if a body were to die within water, it will continue absorbing water until it becomes weakened, structurally, dissolving into fragments, then into the Water itself.

 Because that, truly, is the Nature of Water. It subsumes, consumes, dominates, overcomes. Water will never stop until everything else becomes Water as well.

 Now, am I saying Water is deadly be dint only of its malleability? Air is also just as versatile. Air surrounds & penetrates all. But if you leave something dead outside in the Air... the Earth will reclaim it from Rot first. Air goes with Life. Water engulfs.Water continues its presence until it is dealt with. Water shifts form to fit its surrondings, dampens things to await its release... finds a way. No living thing is capable of fully converting or eliminating Water, so far as I know.

...Almost sounds like some sort of parasitic alien force, doesn't it?

Earth doesn't continue to pile ontop of you, of its own accord, until you become it. Air & Fire have their limits where they do not go... but Water...?

Water... TAKES.

 I'll take a non-Dihydrogen Monoxide based universe anyday.