Blind Waves — Steven Gould

The author of Jumper returns with a near-future SF novel, set in an America whose coastline has been drowned by melting Antarctic ice.

In the world where hundreds of millions of people have been displaced from their homes by the Deluge--a hundred-foot-rise in sea level from melting ice caps--Partricia Beenan is lucky. She is still an American citizen with the right to live on the continent, unlike so many "wetfoots" whose homes lie deep under the waves or the refugees from nations now completely under water.

But Patricia's father chose to live on a floating city of New Galveston, instead of following his congresswomen wife to Washington, and go into the underwater salvage business. Now, several years after his death, it's Patricia's business and her city. She's a wealthy woman, on the city council, well known to local INS commander and the New Galveston police.

But none of that will help Patricia when she stumbles across a recently sunken freighter that has dozens of bodies chained up in its hold and clear evidence that it has been fired upon by an INS ship.

Patricia's evidence of a rogue operation within the INS brings her together with Thomas Beckett, a government investigator assigned to the case. Romance blossoms while they pursue and are pursued by the killers, into the heart of the conspiracy.