This moon. Celios, is one of three that circle the planet Tinoutia. The planet orbits the sun Arduran in the Large Magellanic Cloud.
It is entirely covered in liquid water, which is kept from freezing from a combination of it's hot core, the sun and tidal forces from Tinoutia. It has been this way for a few hundred million of years, but is expected to eventually die out as the moon's core cools down. It'll start by freezing at the surface, then work it's way downward. The weak atmosphere helps keep a little bit of warmth from the heat retention of the water, however it's very mild. At the water's surface, the "air" is 5C. By the time you reach 300 feet above the surface, it can reach -150C.
The oceans on the moon average 1060 meters deep, with the shallowest being 60 meters, and the deepest being 2885 meters. At the bottom of the deepest part, the water is nearly 30C, being very close to the molten core.
The only ripples in the eternally calm waters come space debris hitting the surface. The waves generated can, and will, move along the surface for years, decades, sometimes even centuries. The ones you see could have been originally generated over three hundred years ago. The brief event of chaos will live on in ripples along the surface, growing more peaceful everyday, until they completely fade away, and the moment being forgotten forever.