This is the start of 6 excursions into Brin's universe known as The Uplift Trilogies. The premise is very, very cool. The execution, well, the most beloved is Startide Rising, the second volume of the first trilogy, published three years later. It brought the awards house down, gathering every trophy in sight.
Brin, being a Phd'd astrophysicist and consultant to NASA, is about Big Ideas. I mean galactic-sized Ideas. He's not down there fertilizing the cornfield, he's up in the Big House running the farm. And, as with most chiefs, he sometimes oversteps the literary boundaries with TMI syndrome.
Because I found myself lost in his technical appraisals, conjectures, and descriptions of theoretical conditions on moving a sentient-crafted object—the Sundiver spaceship—into and through the sun's outer layers—the chromosphere and photosphere—to investigate a herd of "magnetovores"—apparent life-forms nicknamed "Sun Ghosts" who nourish from magnetic force fields—and speculate the possibility of them being humanity's patron species. The crew is comprised of various aliens with diverse abilities—known and unknown—plus a handful of humans—our intrepid investigator for "morphological analysis"; the female commander who, underneath a competent persona, hides a "laughing playful inner woman"; a news reporter with Joe Pesci-like hysterics and volatility. The plot and characters are all feasible, it's just the delineative wrappings distanced me from solid, mental visualizations and therefore the welcome mat saying "Believe Me" just wasn't there. As a detective/mystery genre entry, it is quite successful, I've heard. After stripping off all the technobabble, anyway(1).
That said, Sundiver introduces us to a fascinating universe.
You see, no intelligent race has ever busted out of its own solar system without the help of a Patron species. Except humanity. And, by the time we're discovered by the intergalactic civilization that comprises many sentient worlds billions of years old, humans have "uplifted" two, earthbound species itself, that of chimpanzees and bottlenose dolphins. We're seen as unworthy outsiders or pesky ciphers and are called "wolfies" by the aliens with the big brains. Natch, we kinda snuggle into that role and flaunt it—being prideful Americans and all—even though there's plenty of biased MoFos out there who can roll over on us with an easy, obliterating snort.
Further information and a more detailed accounting can be found here at Wiki.
Dead at 245/340.