I think it was a sci-fi, time travel sort of thing. In at least part of the story the main character was on Titanic as it was sinking. I can't remember if the whole story was about the person being on Titanic. I think it wasn't but I'm not sure.
That's a pretty shaky description of the book but it's the best I've got.
I woke up thinking about it yesterday for no good reason and can't remember the name at all.
Thank you!