Ocean of Emptiness by Serena Kay
Approx. 99,370 words.
Published on May 27, 2011.
When Rayan Thorn stumbles across a legendary Starmaid, a space-dwelling, mermaid creature, he sees her as his ticket to freedom. He's been framed for a crime and is stuck on a deadly stardust-mining starship with little chance of survival.
However, when the Starmaid Thallie is kidnapped, will he risk his own freedom to save her? After all, Thallie is the only real friend he's ever had.