I've been looking into water in games and animation, as well as simlatuted water in movies like 2012 and Avater. The general consensus is that water is hard, often using techniques to mask it. It slightly worries me when studios like Naughty Dog (Uncharted) and Blizzard (StarCraft 2) have to cheat it. For example check out 17 seconds on...
It just fills from the botton as a solid shape. Not filling as liquid would.
Having said that though, I have found a Maya plugin called RealFlow. It is also a standalone product that can have its animations exported to Maya. Here is what it claims:
RealFlow, with sister product the RealFlow RenderKit, is a unique fluids and body dynamics software package which allows you to simulate anything from a single drop of water to a massive tsunami crashing across a beach, sweeping debris in its wake.
RealFlow remains the definitive tool for the creation of flawlessly realistic simulations, and has been used to produce some of the most ground-breaking visual effects ever seen, in movies like “Avatar”, “District 9”, “2012”, “GI Joe”, and “The Curious Case of Benjamin Button”, as well as commercials, TV programs, and game cinematics.
I haven't downloaded it so I haven't tried it out to see how difficult or not it is but I'll look at this to see if I can make awesome water.