I suspect it's Tripoint, but many of her stories include the "night-walkers" who are the only people that can remain unsedated during jumps.
Update (to be a real answer):
The protagonist in Tripoint is forced to join the crew of a ship. He is, like the majority of the crew, sedated during "jumps". A rare mutation allows certain people to be able to remain unsedated during jumps, the "fleet navigators", invariably referred to as "night walkers" by the other crew members. The night walkers identify themselves by wearing a unique green tattoo on the forearm.
As the book proceeds we slowly learn that the protagonist is an undiscovered night walker and begins a relationship with Capella, the ship's navigator. As this takes place during the jumps, it remains hidden from the crew who remain sedated. Due to prior history, he does not entirely trust her motives or that of the ship as a whole.
The events of the book lead inexorably to make the ship travel to an abandoned freighter near Tripoint. The various plot lines are wrapped up, and the protagonist remains on his new ship with Capella as they decide to leave charted space.