Startide Rising, David Brin
This is the second in Brin's Uplift series. This story is set parallel to his third book. Both telling of events in the galaxy after mankind discovers a graveyard of ancient spaceships. All the older alien races feel they must know everything... by force if necessary. This book follows the dolphin and human crew of the ship that made the discovery as it flees. It's one I really enjoy for it's battles against overwhelming odds, interesting characters, and a fair grasp of science (although some of it is made up science.)