Wow. This book was a huge disappointment. Mermaids have always intrigued me. And I love fairytale retellings. Those two elements should have made it a four or five star read.
What ruined it for me? Hmm... I'm not quite sure. Maybe it was the Lo/Naida confusion? Maybe it was the love triangle that wasn't well done? Maybe it was Celia's relationship with her sisters? Maybe it was Celia herself being somewhat annoying? Maybe it was the lack of mythology explaining the ocean girls and how they came to be, and the lack of reasons for Celia and her sisters' powers? Maybe it was the inclusion of the Fenris when they had nothing to do with the story! I mean, mermaids and werewolves? Really?
Perhaps it was all of those things rolled up together with mediocre writing. When the beautiful cover and the intriguing synopsis promised so much more.
I do not recommend Fathomless. And it's a shame, because I had this on my to-read list for ages and was super excited to start reading it.