New observations of Titan suggest evidence of oceans of liquid water, below the surface.  Scientists have suspected this to be the case for a long time, but released their new findings today on line in the journal, Science.  The Cassini probe has been in orbit around Saturn since 2004, and makes passes close to Titan from time to time.  The probe has been measuring the mass of Titan, watching the surface "flex" under the intense gravitational forces it experiences with each orbit of Saturn.  It is unknown if it is water under the surface of Titan, but scientists are convinced there is a liquid layer!

"The strong way in which Titan deformed in response to Saturn hints that the moon has quite a flexible interior. This adds evidence to suggestions that an ocean lies concealed beneath a relatively thin shell 60 miles (100 kilometers) or less thick.

http://www.space.com/16348-titan-ocean-saturn-moon.html