Ark — Stephen Baxter

It's the year 2030. The oceans have risen rapidly, and soon the entire planet will be submerged. But the discovery of another life-sustaining planet light years away gives those who remain alive hope. Only a few will be able to make the journey-Holle Groundwater is one of the candidates. If she makes the cut, she will live. If not, she will be left to face a watery death...