Terragen 4 (free version)
TRAPPIST-1 is a tiny star some 39 lightyears away. Recently, a very compact system of seven earth-sized planets has been discovered around this star. Three of them are likely to be within the habitable zone.
TRAPPIST-1f is about the size of the Earth, but only 0.68 times it's density. This makes it a reasonable candidate for a water world. The planet is so close to it's star that tidal forced will have halted its rotation long ago. Thus the planet would have a permanent dayside and a permanent nightside. At least on the dayside, the ocean may be liquid. TRAPPIST-1f is cooler than Earth, with an estimated equilibrium temperature of -54°C (Earth: -15°C).
More information about TRAPPIST-1:
http://www.trappist.one/