Deep Trouble

This cover is one of the first I remember from when I was a kid. We used to take shore vacations as a family every year, and sharks were always such a fascinating and scary thing to me. They can be just below you, and you don't even know! 
I honestly didn't remember the story that much, so I was incredibly surprised with the inclusion of mermaids. I think my brain just stuck with the shark cover and that was about it. 
Very enjoyable though, and it was nice to be surprised. The research stuff described, as well as the different marine life on board, definitely had me hooked and wanting more of that background info. 
Personally a 5/5* for me. The setting change was a bit hit.