I need some cool mermaid/ocean centric books to read!

I adore the ocean and I love mermaids. I would love to read a good mermaid book, any genre! could be gory horror or just a good ol pirate mermaid deal.

Also looking for any books set around/near the ocean. Could be something pirate, or maybe a lighthouse keeper, or about an ocean creature!

Please send in your recs!!