Neo-Dolphins are the second client species of humans and are mid-way through being genetically engineered. The human uplift board evaluates the physical development and mental achievements of all their clients for purposes of reproductive priority and speeding directed evolution.

Neo-Dolphins are Stage-2 Clients, and recently got their own Starship, Streaker (Streaker's discoveries later caused controversy among the oxygen-breathing sapient species). Neo-Dolphins are at a relatively early stage of Uplift, and this has several consequences which are important in the plots of the stories: the optimal genetic mix for Neo-Dolphins has not yet been determined, and some of the newer genetic mixes become dangerous to colleagues when under stress; there are significant differences between older and younger Neo-Dolphins, in particular older individuals find it more difficult to speak; and they have to struggle against tendencies to slip into atavistic behaviours such as the Whale Dream and rescue fever (which leads them to beach themselves). Their fins are elongated as a first step toward becoming arms. Most professional neo-dolphins have a neural socket that allows them to directly access controls for computers or machines such as their six-legged walking exo-skeleton as its robotic arms.

Under periods of prolonged stress a new-dolphin may go feral and return to speaking (and thinking) only in the primal sequels and clicks of natural unaltered dolphins. Speaking in Anglic is difficult for neo-dolphins but necessary to convey complex and technical ideas. Trinary is a compromise language between primal and Anglic, invented to help dolphins during the uplift transition. They are some of the best pilots in the Five Galaxies because their aquatic origins give them excellent instincts for 3-D maneuvers. They are also important in planetary warfare because most Galactics are unaware of the strategic potential of the sea.