The Face of the Waters

On the ocean world of Hydros -- a planet with no land beyond a scatter of artificial floating islands -- the human settlers of Sorve commit an offense against the native aquatic Hydrans serious enough to get their community banished, forbidden from settling on any other island. With nowhere else to go, Sorve's people set out across the water in a makeshift flotilla, chasing rumors of a mythical island called the Face of the Waters that may or may not exist, forced to reckon with what they owe the world they've spent generations treating as theirs. A Robert Silverberg novel of exile and search, told through Sorve's displaced islanders.