It's about a Highschool girl who becomes the captain of a ship because her father died (in this world the only way for a person to become a pirate captain is to inherit the position when a parent dies). As for being good, it's very up and down, the first story arch was really good, it did enough to hook me in, the one after that started out slow, gradually got better and better before a fairly anti-climatic end. I'd definitely recommend it though, it has some fairly interesting characters.