Startide rising.

David Brin: “Startide Rising” (1983) This is a sci fi story about a Terran (Earth) crew of neo-dolphins and humans on the starship “The Streaker”. Their mission is to find information about the first Galactic race, which existed billions of yeas ago. The neo-dolphins are dolphins which have gone through the "Uplift" process, which creates through genetic engineering more intelligent ...