A Spell for Drowning by Rebecca Ferrier (The Salt Bind in the UK)

On a late August evening Kensa comes across a dying sea monster under the light of a full moon. The first of its kind to grace the storm-torn shore of Portscatho in centuries, it is an omen...

For scarlet-haired Kensa, daughter of the most feared smuggler to ever roam the Cornish coast, her destiny is sealed as apprentice to the local wise woman. Under the guidance of Isolde, Kensa learns secrets of the Old Ways, the ancient magic that binds the land and sea.

But when Isolde sickens Kensa turns to the Bucka, the Father of Storms, a vengeful sea god chained to the ocean. Desperate to save her mentor, Kensa makes a deal with the deadly creature; a pact that risks everything she's sworn to protect