Uplift

Startide Rising picks up about 200 years after Sundiver left off. The first mostly-dolphin starship crew is assembled and sent on a survey mission. Upon finding a huge derelict fleet of unknown origin and sending a message home about it, several hostile races hound the small survey craft until she crashes in the ocean of a metal-rich waterworld. Apparently, the hostiles are all quasi-fanatical races who believe in the eventual return of the Progenitors, the race or races who began the practice of Uplift.

Across known space, Humanity is a rare example of a species that achieved sentience and a starfaring civilization without the evident help of a Patron race. In the eyes of some aliens, this makes them unique; in others, it makes them outcasts. Humans have earned themselves a tenuous status in Galactic society, however, as they had already Uplifted two other races - chimpanzees and dolphins - by the time of First Contact.