Some books fail to live up to nostalgia-tinged memories. Some books remain solid years later. And some books are even better than you remember. This one's definitely in the latter category.
It's a fairy tale first and foremost, so don't read it if you're looking for detailed worldbuilding or rules of magic. It works by fairy-tale logic. Metaphor is important. Things come in threes. Your heart's desire pays for itself, if only you can figure out what it is.
Mostly, it's the language I love it for. It perfectly captures the sea--its rage, its beauty, its possessiveness, its indifference. It shows that the scattering of huts on the shore can be just as magical as the palaces of pearl beneath the waves. There are images here that have stayed with me for decades, and others I'm excited to rediscover each time I reread.