The Chainbreakers.

"The Chainbreakers" by Julian Randall is a children's/YA fantasy novel about twelve-year-old Violet Moon, who is next in line to become a Reaper like her father. When her father is abducted by the Children of the Shark, Violet must take on the role of captain of the Mooney, a magical boat used to rescue souls. Despite opposition from her first mate and the Chainbreakers Council, Violet is determined to find her father and faces challenges along the way. This propulsive fantasy adventure explores themes of grief, legacy, and revenge, and features a diverse cast of characters. [Extracted from the article]