The Songs of Distant Earth is an intelligent science-fiction novel with a, rare for the genre, character driven story.
With the Sun about to die, the people of the earth build seed ships to save humanity, sending them across the galaxy to populate habitable planets. One of these planets is Thalassa, a planet dominated by water.
The book deals with the effects of this history on the populace, together with the arrival of people from Earth hundreds of years after the birth of humanity on Thalassa. It is a wonderful and interesting read.