In order to be a "faster than light" pilot, you have to remove your heartbeat by getting a continuous rotary pump in place of your heart. (perhaps inspired by the rotary Mazdas that don't seem to be around any more.)
But what happens when you achieve the much coveted status of Pilot with a successful transformation, and then meet an intriguing guy that you really like/love who has an extremely strong time sense...?
I read it many years ago, more than once, as much for the romantic attraction as for the drama and speculation about how we might modify the human body for various uses, from deep sea living to space travel... I think there's a sequel that continues the characters.