By David Brin
Bantam 1983/Orbit 1997
ISBN 1 85723 372 7
The second novel in the Uplift Series, and a winner of both the Hugo and Nebula Awards, Startide Rising is, in my opinion, a much superior novel to Sundiver.
Once again we have a hazy backstory - the discovery of a suspected Progenitor fleet as well as the mission/origins of the major human characters Thomas Orley and Gillian Baskin - that is given in sketchy detail at best, as well as a scientist with a dubious hidden agenda. Though, this time around the motivations and conflicts of the characters are better developed and have more depth.
As the rival fleets of Galactics arrive, we begin to learn a little more about the rivalries and drivers of Major Race politics, as well as how each race has developed the technology lineage it has been entrusted with. It is this detail that draws me, as a reader, on into the story. The motivations and needs of the various Client and Patron races, and the fact that many Client/Patron relationships have hidden conflicts are nicely detailed, though I did start to need a score card to keep track of who was a Client or Patron of whom.
A very good read and repays reading again.
There's a review at Wikipedia that links through to some useful Uplift sites.
Other books by David Brin: Sun Diver     The Uplift War