There are 2 books in the Beneath the Haunting Sea series.
The Beneath the Haunting Sea series does not have a new book coming out soon. The latest book, Beyond the Shadowed Earth (Book 2), was published in January 2020.
The first book in the Beneath the Haunting Sea series, Beneath the Haunting Sea, was published in January 2018.
The Beneath the Haunting Sea series primarily falls into the Fantasy genre. This young adult series was written for ages 12-17, but can be enjoyed by adults too.